* use `configuration::config()` for max bytes

* Update integration_tests.rs

* Update paras_registrar.rs

* remove consts

* add asserts for non-zero

* more const clean up

* cargo run --release --features=runtime-benchmarks -- benchmark --chain=kusama-dev --steps=50 --repeat=20 --pallet=runtime_common::paras_registrar --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/kusama/src/weights/runtime_common_paras_registrar.rs

* cargo run --release --features=runtime-benchmarks -- benchmark --chain=westend-dev --steps=50 --repeat=20 --pallet=runtime_common::paras_registrar --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --header=./file_header.txt --output=./runtime/westend/src/weights/runtime_common_paras_registrar.rs

* add checks to `MAX_CODE_SIZE`

* re-pot MAX_POV_SIZE

* check pov limit in runtime

* POV_BOMB_LIMIT multiplier

* fix compile

* Update configuration.rs

* Update node/primitives/src/lib.rs

* fix test

Co-authored-by: Parity Bot <admin@parity.io>

* skeleton for dispute-coordinator

* add coordinator and participation message types

* begin dispute-coordinator DB

* functions for loading

* implement strongly-typed DB transaction

* add some tests for DB transaction

* core logic for pruning

* guide: update candidate-votes key for coordinator

* update candidate-votes key

* use big-endian encoding for session, and implement upper bound generator

* finish implementing pruning

* add a test for note_current_session

* define state of the subsystem itself

* barebones subsystem definition

* control flow

* more control flow

* implement session-updating logic

* trace

* control flow for message handling

* Update node/core/dispute-coordinator/src/lib.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update node/subsystem/src/messages.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* some more control flow

* guide: remove overlay

* more control flow

* implement some DB getters

* make progress on importing statements

* add SignedDisputeStatement struct

* move ApprovalVote to shared primitives

* add a signing-payload API to explicit dispute statements

* add signing-payload to CompactStatement

* add relay-parent hash to seconded/valid dispute variatns

* correct import

* type-safe wrapper around dispute statements

* use checked dispute statement in message type

* extract rolling session window cache to subsystem-util

* extract session window tests

* approval-voting: use rolling session info cache

* reduce dispute window to match runtime in practice

* add byzantine_threshold and supermajority_threshold utilities to primitives

* integrate rolling session window

* Add PartialOrd to CandidateHash

* add Ord to CandidateHash

* implement active dispute update

* add dispute messages to AllMessages

* add dispute stubs to overseer

* inform dispute participation to participate

* implement issue_local_statement

* implement `determine_undisputed_chain`

* fix warnings

* test harness for dispute coordinator tests

* add more helpers to test harness

* add some more helpers

* some tests for dispute coordinator

* ignore wrong validator indices

* test finality voting rule constraint

* add more tests

* add variants to network bridge

* fix test compilation

* remove most dispute coordinator functionality

as of #3222 we can do most of the work within the approval voting subsystem

* Revert "remove most dispute coordinator functionality"

This reverts commit 9cd615e8

.

* Use thiserror

Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>

* Update node/core/dispute-coordinator/src/lib.rs

Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>

* extract tests to separate module

* address nit

* adjust run_iteration API

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>
Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>

* create newtype for ValidationCodeHash

* pvf: fix tests compilation

* primitives: fix test compilation

* replace HistoricalValidationCode usages with ValidationCodeByHash

* runtime-api: tabify tests file

* update implementers guide

* Make ParaId value of public paras non-discretionary

* Fixes

* Fixes

* fix tests

* fix benchmark tests

* dont use hardcoded number

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Remove signature verification in backing.

`SignedFullStatement` now signals that the signature has already been
checked.

* Remove unused check_payload function.

* Introduced unchecked signed variants.

* Fix inclusion to use unchecked variant.

* More unchecked variants.

* Use unchecked variants in protocols.

* Start fixing statement-distribution.

* Fixup statement distribution.

* Fix inclusion.

* Fix warning.

* Fix backing properly.

* Fix bitfield distribution.

* Make crypto store optional for `RuntimeInfo`.

* Factor out utility functions.

* get_group_rotation_info

* WIP: Collator cleanup + check signatures.

* Convenience signature checking functions.

* Check signature on collator-side.

* Fix warnings.

* Fix collator side tests.

* Get rid of warnings.

* Better Signed/UncheckedSigned implementation.

Also get rid of Encode/Decode for Signed! *party*

* Get rid of dead code.

* Move Signed in its own module.

* into_checked -> try_into_checked

* Fix merge.

* Wip

* Increase proposer timeout.

* WIP.

* Better timeout values now that we are going to be connected to all nodes. (#2778)

* Better timeout values.

* Fix typo.

* Fix validator bandwidth.

* Fix compilation.

* Better and more consistent sizes.

Most importantly code size is now 5 Meg, which is the limit we currently
want to support in statement distribution.

* Introduce statement fetching request.

* WIP

* Statement cache retrieval logic.

* Review remarks by @rphmeier

* Fixes.

* Better requester logic.

* WIP: Handle requester messages.

* Missing dep.

* Fix request launching logic.

* Finish fetching logic.

* Sending logic.

* Redo code size calculations.

Now that max code size is compressed size.

* Update Cargo.lock (new dep)

* Get request receiver to statement distribution.

* Expose new functionality for responding to requests.

* Cleanup.

* Responder logic.

* Fixes + Cleanup.

* Cargo.lock

* Whitespace.

* Add lost copyright.

* Launch responder task.

* Typo.

* info -> warn

* Typo.

* Fix.

* Fix.

* Update comment.

* Doc fix.

* Better large statement heuristics.

* Fix tests.

* Fix network bridge tests.

* Add test for size estimate.

* Very simple tests that checks we get LargeStatement.

* Basic check, that fetching of large candidates is performed.

* More tests.

* Basic metrics for responder.

* More metrics.

* Use Encode::encoded_size().

* Some useful spans.

* Get rid of redundant metrics.

* Don't add peer on duplicate.

* Properly check hash

instead of relying on signatures alone.

* Preserve ordering + better flood protection.

* Get rid of redundant clone.

* Don't shutdown responder on failed query.

And add test for this.

* Smaller fixes.

* Quotes.

* Better queue size calculation.

* A bit saner response sizes.

* Fixes.

* guide: declare one para as a collator

* add ParaId to Declare messages and clean up

* fix build

* fix the testerinos

* begin adding keystore to collator-protocol

* remove request_x_ctx

* add core_for_group

* add bump_rotation

* add some more helpers to subsystem-util

* change signing_key API to take ref

* determine current and next para assignments

* disconnect collators who are not on current or next para

* add collator peer count metric

* notes for later

* some fixes

* add data & keystore to test state

* add a test utility for answering runtime API requests

* fix existing collator tests

* add new tests

* remove sc_keystore

* update cargo lock

Co-authored-by: Andronik Ordian <write@reusable.software>

* code stored in para + modify CandidateDescriptor.

* WIP: digest + some more impl

* validation_code_hash in payload + check in inclusion

* check in client + refator

* tests

* fix encoding indices

* remove old todos

* fix test

* fix test

* add test

* fetch validation code inside collation-generation from the relay-chain

* HashMismatch -> PoVHashMismatch + miscompilation

* refactor, store hash when needed

* storage rename: more specific but slightly too verbose

* do not hash on candidate validation, fetch hash instead

* better test

* fix test

* guide updates

* don't panic in runtime

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* dispute types

* add Debug to dispute primitives in std and InherentData

* use ParachainsInherentData on node-side

* change inclusion_inherent to paras_inherent

* RuntimeDebug

* add type parameter to PersistedValidationData users

* fix test client

* spaces

* fix collation-generation test

* fix provisioner tests

* remove references to inclusion inherent

* Remove stuff out of the runtime that does not belong there.

There might be more, but it is a start.

* White space fixes.

* Fix tests.

* Leave whitespace in ui tests alone.

* Add back zstd for no reason.

* Fix browser wasm (hopefully)

* add consensus log type

* origin and issue force_approve

* add origin in runtimes

* ref API

* scrape force_approve digest from header

* add parent_hash to BlockEntry

* add block_number to block entry and force_approve skeleton

* implement and plug in force-approve

* test force_approve

* test force_approve extraction

* westend runtime

* Update node/core/approval-voting/src/approval_db/v1/mod.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* rename

* Update runtime/parachains/src/initializer.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Unify maximum supported PoV size a bit.

* Use MAX_POV_SIZE also in `HostConfiguration`.

* Fix types.

* Additional logging for polkadot network protocols

* Additional log

* Update node/network/bitfield-distribution/src/lib.rs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Update node/network/availability-distribution/src/responder.rs

* Added additional chunk info

* Added additional peer info

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Introduce collation fetching protocol

also move to mod.rs

* Allow `PeerId`s in requests to network bridge.

* Fix availability distribution tests.

* Move CompressedPoV to primitives.

* Request based collator protocol: validator side

- Missing: tests
- Collator side
- don't connect, if not connected

* Fixes.

* Basic request based collator side.

* Minor fix on collator side.

* Don't connect in requests in collation protocol.

Also some cleanup.

* Fix PoV distribution

* Bump substrate

* Add back metrics + whitespace fixes.

* Add back missing spans.

* More cleanup.

* Guide update.

* Fix tests

* Handle results in tests.

* Fix weird compilation issue.

* Add missing )

* Get rid of dead code.

* Get rid of redundant import.

* Fix runtime build.

* Cleanup.

* Fix wasm build.

* Format fixes.

Thanks @andronik !

* add full data messages

* handle new messages

* flip condition

* skeleton

* skeleton aux-schema module

* start approval types

* start aux schema with aux store

* doc

* finish basic types

* start approval types

* doc

* finish basic types

* write out schema types

* add debug and codec impls to approval types

* add debug and codec impls to approval types

also add some key computation

* add debug and codec impls to approval types

* getters for block and candidate entries

* grumbles

* remove unused AssignmentId

* load_decode utility

* implement DB clearing

* function for adding new block entry to aux store

* start `canonicalize` implementation

* more skeleton

* finish implementing canonicalize

* tag TODO

* implement a test AuxStore

* add allow(unused)

* basic loading and deleting test

* block_entry test function

* add a test for `add_block_entry`

* ensure range is exclusive at end

* test clear()

* test that add_block sets children

* add a test for canonicalize

* extract Pre-digest from header

* utilities for extracting RelayVRFStory from the header-chain

* add approval voting message types

* approval distribution message type

* subsystem skeleton

* state struct

* add futures-timer

* prepare service for babe slot duration

* more skeleton

* better integrate AuxStore

* RelayVRF -> RelayVRFStory

* canonicalize

* implement some tick functionality

* guide: tweaks

* check_approval

* more tweaks and helpers

* guide: add core index to candidate event

* primitives: add core index to candidate event

* runtime: add core index to candidate events

* head handling (session window)

* implement `determine_new_blocks`

* add TODO

* change error type on functions

* compute RelayVRFModulo assignments

* compute RelayVRFDelay assignments

* fix delay tranche calc

* assignment checking

* pluralize

* some dummy code for fetching assignments

* guide: add babe epoch runtime API

* implement a current_epoch() runtime API

* compute assignments

* candidate events get backing group

* import blocks and assignments into DB

* push block approval meta

* add message types, no overseer integration yet

* notify approval distribution of new blocks

* refactor import into separate functions

* impl tranches_to_approve

* guide: improve function signatures

* guide: remove Tick from ApprovalEntry

* trigger and broadcast assignment

* most of approval launching

* remove byteorder crate

* load blocks back to finality, except on startup

* check unchecked assignments

* add claimed core to approval voting message

* fix checks

* assign only to backing group

* remove import_checked_assignment from guide

* newline

* import assignments

* abstract out a bit

* check and import approvals

* check full approvals from assignment import too

* comment

* create a Transaction utility

* must_use

* use transaction in `check_full_approvals`

* wire up wakeups

* add Ord to CandidateHash

* wakeup refactoring

* return candidate info from add_block_entry

* schedule wakeups

* background task: do candidate validation

* forward candidate validation requests

* issue approval votes when requested

* clean up a couple TODOs

* fix up session caching

* clean up last unimplemented!() items

* fix remaining warnings

* remove TODO

* implement handle_approved_ancestor

* update Cargo.lock

* fix runtime API tests

* guide: cleanup assignment checking

* use claimed candidate index instead of core

* extract time to a trait

* tests module

* write a mock clock for testing

* allow swapping out the clock

* make abstract over assignment criteria

* add some skeleton tests and simplify params

* fix backing group check

* do backing group check inside check_assignment_cert

* write some empty test functions to implement

* add a test for non-backing

* test that produced checks pass

* some empty test ideas

* runtime/inclusion: remove outdated TODO

* fix compilation

* av-store: fix tests

* dummy cert

* criteria tests

* move `TestStore` to main tests file

* fix unused warning

* test harness beginnings

* resolve slots renaming fallout

* more compilation fixes

* wip: extract pure data into a separate module

* wip: extract pure data into a separate module

* move types completely to v1

* add persisted_entries

* add conversion trait impls

* clean up some warnings

* extract import logic to own module

* schedule wakeups

* experiment with Actions

* uncomment approval-checking

* separate module for approval checking utilities

* port more code to use actions

* get approval pipeline using actions

* all logic is uncommented

* main loop processes actions

* all loop logic uncommented

* separate function for handling actions

* remove last unimplemented item

* clean up warnings

* State gives read-only access to underlying DB

* tests for approval checking

* tests for approval criteria

* skeleton test module for import

* list of import tests to do

* some test glue code

* test reject bad assignment

* test slot too far in future

* test reject assignment with unknown candidate

* remove loads_blocks tests

* determine_new_blocks back to finalized & harness

* more coverage for determining new blocks

* make `imported_block_info` have less reliance on State

* candidate_info tests

* tests for session caching

* remove println

* extricate DB and main TestStores

* rewrite approval checking logic to counteract early delays

* move state out of function

* update approval-checking tests

* tweak wakeups & scheduling logic

* rename check_full_approvals

* test that assignment import updates candidate

* some approval import tests

* some tests for check_and_apply_approval

* add 'full' qualifier to avoid confusion

* extract should-trigger logic to separate function

* some tests for all triggering

* tests for when we trigger assignments

* test wakeups

* add block utilities for testing

* some more tests for approval updates

* approved_ancestor tests

* new action type for launch approval

* process-wakeup tests

* clean up some warnings

* fix in_future test

* approval checking tests

* tighten up too-far-in-future

* special-case genesis when caching sessions

* fix bitfield len

Co-authored-by: Andronik Ordian <write@reusable.software>

* PVD: `block_number`->`relay_parent_number`

* ValidationParams: `relay_chain_height`->`relay_parent_number`

* Expose DMQ MQC hash as a well-known-key

This way the relay storage merkle proofs will be able to obtain the DMQ
MQC hash and we will be able to remove the it from the
PersistedValidationData struct.

* PersistedValidationData: Remove HRMP MQC heads

* PersistedValidationData: Remove `dmq_mqc_head`

* Expose the HRMP ingress channel index as a well-known-key

This way a parachain (PVF and collator) can find all the parachains that
have an outbound channel to the given one. That allows in turn to find
all the inbound channels for the given para.

Having access to that allows the parachain to get the same information
as the hrmp_mqc_heads now provide.

* Rename `relay_storage_root` to `relay_parent_storage_root`

* upgrade codec and bitvec

* "Update Substrate"

Co-authored-by: parity-processbot <>

* Add memory-lru cache to runtime-api

* Add cache.rs

* Adds MallocSizeOf

* Review nits

* Add a cached requests metric

* More review nits

* Some more review nits

* initial impl approval distribution

* initial tests and fixes

* batching seems difficult: different peers have different needs

* bridge: fix test after merge

* some guide updates

* only send assignments to peers who know about the block

* fix a test, add approvals test

* simplify

* do not send assignment to peers for finalized blocks

* guide: protocol input and output

* one more test

* more comments, logs, initial metrics

* fix a typo

* one more thing: early return when reimporting a thing locally

* Put parachain head hash into `CandidateDescriptor`

* Update guide

* Add some checks

* collation-generation: use persisted validation data

* node: remote FullValidationData API

* runtime: remove FullValidationData API

* backing tests: use persisted validation data

* FullCandidateReceipt: use persisted validation data

This is not a big change since this type is not used anywhere

* Remove ValidationData and TransientValidationData

Also update the guide

* scheduler: handle re-scheduling around finalization correctly

* also make sure parathreads get cleaned

* run scheduling in finalization

* Remove stray println!

* Update the schedule call site in inclusion inherent

* Clarify subtlety around SessionStartBlock

* Remove double semi-colon

* reschedule prior to `availability_cores` and in on-initialize

* improve docs

* fix line

* more doc reformat

* remove unneeded call

* avoid unnecessary scheduling on initialize

* split `clear` and `schedule

* Update runtime/parachains/src/scheduler.rs

Co-authored-by: Sergei Shulepov <sergei@parity.io>

Co-authored-by: Sergei Shulepov <sergei@parity.io>

* don't modify inherent data on heavy block

* write up current thinking on block weight detection

* extract inherent inclusion check into its own function

* put heavy block check into runtime

* the `inclusion` inherent call is Operational, not Mandatory

This resolves a lot of the trickiness about this issue, because
we no longer need to override or supplant any existing proposer
logic; the existing logic should exhibit these behaviors:

- the `inclusion` inherent is prioritized over standard transactions
- but if it's too heavy, i.e. in case of runtime upgrade, it'll be
  dropped in favor of that.

It is my belief that allowing the proposer to just not include
this data won't have any adverse effects: it's equivalent to replacing
them with empty versions of themselves, which the `ProvideInherent`
impl already does.

* Revert "the `inclusion` inherent call is Operational, not Mandatory"

This reverts commit e58858d1.

* Revert "write up current thinking on block weight detection"

This reverts commit fd587b80.

* Revert "don't modify inherent data on heavy block"

This reverts commit 38299d3c

.

* add backed candidate block weight assumption to configuration

* Limit backed candidates according to a candidate weight heuristic.

This approach replaces making the inclusion inherent non-mandatory.
It's still not ideal in that we have to configure a heuristic for
how much each backed candidate 'weighs', instead of directly
measuring it somehow.

This approach also never truncates the signed bitfields. The
rationale for that depends on some assumptions:

- processing the signed bitfields is cheap compared to the
  backed candidates
- it is beneficial to the progress of the relay chain
  to update the signed bitfields even if not all backed candidates
  are updated

* simplify limit_backed_candidates and weight assumption

* don't trust the provisioner to fairly distribute candidates

* use saturating subtraction

* empty commit to restart ci

* use new mechanism for getting max block weight

* apply weight refunds to the inclusion inherent

This makes some assumptions about fundamental weights, which are
encapsulated as constants. From there, it lets Substrate know
what the actual computed weight of the inherent is.

* use a correct fixed weight for the inclusion inherent

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* use dynamic inclusion weight so we reduce calculated weight when excluding candidates

* don't double-count this intrinsic's weight in the block weight

* add unit tests of fn limit_backed_candidates

* add tests that the inclusion inherent's weight correctly updates

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Add well_known_keys

* Reorder HrmpChannel and HostConfiguration members

* abridged versions and well known keys tests

* Add some comments

* Add a note on generation of the prefixes

and other magic values

* Recommend accessing the well known values through abridged structs

* Cont.: Implement the state root obtaining during inclusion

During inclusion now we obtain the storage root by passing it through
the inclusion_inherent.

* Fix tests

* Bump rococo spec version

* Reorder the parent header into the end

of the inclusion inherent.

When the parent header is in the beginning, it shifts the other two
fields, so that a previous version won't be able to decode that. If
we put the parent header in the end, the other two fields will stay
at their positions, thus make it possible to decode with the previous
version.

That allows us to perform upgrade of rococo runtime without needing of
simultanuous upgrade of nodes and runtime, or restart of the network.

* Squash a stray tab

* Don't initialize block when calling runtime APIs

* Adapt check_validation_outputs

We split the code path for the inclusion and for the commitments checking.

* Slap #[skip_initialize_block] on safe runtime APIs

That is, those that should not be affected by this attribute

* Make `Scheduled` not ephemeral

So that it is persisted in the storage and ready to be inspected
by the runtime APIs. This is in contrast to what was before, where we
would remove the storage entry and then rely on the scheduling performed
by `on_initialize` again.

* Add a big fat comment

* Typos

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* Move session change to the end of the current block

Previously, it was the beginning of the next block. This allows us to
put #[skip_initialize_block]

* Update tests

* Fix a test in paras registrar

Also refactor it a bit so the next time there are more chances this kind
of issue is diagnosed quicker.

* Add for_runtime_api to inclusion's check_validation_outputs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* guide: add candidate information to OccupiedCore

* add descriptor and hash to occupied core type

* guide: add candidate hash to inclusion

* runtime: return candidate info in core state

* bitfield signing: stop querying runtime as much

* minimize going to runtime in availability distribution

* fix availability distribution tests

* guide: remove para ID from Occupied core

* get all crates compiling

* refactor View to include finalized_number

* guide: update the NetworkBridge on BlockFinalized

* av-store: fix the tests

* actually fix tests

* grumbles

* ignore macro doctest

* use Hash::repeat_bytes more consistently

* broadcast empty leaves updates as well

* fix issuing view updates on empty leaves updates

* guide: merge backing and approval keys

* bump substrate master & update primitives

* use new SessionInfo struct in session_info

* session keys upgrade for Polkadot

* kusama & westend runtimes

* bump westend, kusama, and polkadot versions

* add session key to rococo & test-runtime

* update prepare-test-net to latest subkey

* update chain specs to support new para_assignment session key

* get cargo.lock from master

* formatting

* update kill_storage based on substrate master

* fix test-service

* assgn -> asgn

* use session info module for assignment session key

* Adds consistency checks for the `HostConfiguration`

Besides that it fixes the chain specs to make the consistency checks happy.

* Update runtime/parachains/src/configuration.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Review feedback and test fixes etc

* Update

* More

* I'm an idiot

* Fix tests...

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

Because of a bug in the test script, we didn't stopped CI when the main
tests are failed.

* guide: non-semantic changes

* guide: update per the issue description

* GetBackedCandidates operates on multiple hashes now

* GetBackedCandidates still needs a relay parent

* implement changes specified in guide

* distinguish between various occasions for canceled oneshots

* add tracing info to getbackedcandidates

* REVERT ME: add tracing messages for GetBackedCandidates

Note that these messages are only sometimes actually passed on to the
candidate backing subsystem, with the consequence that it is
unexpectedly frequent that the provisioner fails to create its
provisionable data.

* REVERT ME: more tracing logging

* REVERT ME: log when CandidateBackingJob receives any message at all

* REVERT ME: log when send_msg sends a message to a job

* fix candidate-backing tests

* streamline GetBackedCandidates

This uses table.attested_candidate instead of table.get_candidate, because
it's not obvious how to get a BackedCandidate from just a
CommittedCandidateReceipt.

* REVERT ME: more logging tracing job lifespans

* promote warning about job premature demise

* don't terminate CandiateBackingJob::run_loop in event of failure to process message

* Revert "REVERT ME: more logging tracing job lifespans"

This reverts commit 7365f2fb.

* Revert "REVERT ME: log when send_msg sends a message to a job"

This reverts commit 58e46aad.

* Revert "REVERT ME: log when CandidateBackingJob receives any message at all"

This reverts commit 0d6f3841.

* Revert "REVERT ME: more tracing logging"

This reverts commit 675fd262.

* Revert "REVERT ME: add tracing messages for GetBackedCandidates"

This reverts commit e09e1564.

* formatting

* add logging message to CandidateBackingJob::run_loop start

* REVERT ME: add tracing to candidate-backing job creation

* run candidatebacking loop even if no assignment

* use unique error variants for each canceled oneshot

* Revert "REVERT ME: add tracing to candidate-backing job creation"

This reverts commit 8ce5f4f0.

* try_runtime_api more to reduce silent exits

* add sanity check that returned backed candidates preserve ordering

* remove redundant err attribute

* guide: move erasure-root to candidate descriptor

* primitives: move erasure root to descriptor

* guide: unify candidate commitments and validation outputs

* primitives: unify validation outputs and candidate commitments

* parachains-runtime: fix fallout

* runtimes: fix fallout

* collation generation: fix fallout

* fix stray reference in primitives

* fix fallout in node-primitives

* fix remaining fallout in collation generation

* fix fallout in candidate validation

* fix fallout in runtime API subsystem

* fix fallout in subsystem messages

* fix fallout in candidate backing

* fix fallout in availability distribution

* don't clone

* clone

Co-authored-by: Sergei Shulepov <sergei@parity.io>

* guide: fix formatting for SessionInfo module

* primitives: SessionInfo type

* punt on approval keys

* ah, revert the type alias

* session info runtime module skeleton

* update the guide

* runtime/configuration: sync with the guide

* runtime/configuration: setters for newly added fields

* runtime/configuration: set codec indexes

* runtime/configuration: update test

* primitives: fix SessionInfo definition

* runtime/session_info: initial impl

* runtime/session_info: use initializer for session handling (wip)

* runtime/session_info: mock authority discovery trait

* guide: update the initializer's order

* runtime/session_info: tests skeleton

* runtime/session_info: store n_delay_tranches in Configuration

* runtime/session_info: punt on approval keys

* runtime/session_info: add some basic tests

* Update primitives/src/v1.rs

* small fixes

* remove codec index annotation on structs

* fix off-by-one error

* validator_discovery: accept a session index

* runtime: replace validator_discovery api with session_info

* Update runtime/parachains/src/session_info.rs

Co-authored-by: Sergei Shulepov <sergei@parity.io>

* runtime/session_info: add a comment about missing entries

* runtime/session_info: define the keys

* util: expose connect_to_past_session_validators

* util: allow session_info requests for jobs

* runtime-api: add mock test for session_info

* collator-protocol: add session_index to test state

* util: fix error message for runtime error

* fix compilation

* fix tests after merge with master

Co-authored-by: Sergei Shulepov <sergei@parity.io>