* 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

* 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

* drop in tracing to replace log

* add structured logging to trace messages

* add structured logging to debug messages

* add structured logging to info messages

* add structured logging to warn messages

* add structured logging to error messages

* normalize spacing and Display vs Debug

* add instrumentation to the various 'fn run'

* use explicit tracing module throughout

* fix availability distribution test

* don't double-print errors

* remove further redundancy from logs

* fix test errors

* fix more test errors

* remove unused kv_log_macro

* fix unused variable

* add tracing spans to collation generation

* add tracing spans to av-store

* add tracing spans to backing

* add tracing spans to bitfield-signing

* add tracing spans to candidate-selection

* add tracing spans to candidate-validation

* add tracing spans to chain-api

* add tracing spans to provisioner

* add tracing spans to runtime-api

* add tracing spans to availability-distribution

* add tracing spans to bitfield-distribution

* add tracing spans to network-bridge

* add tracing spans to collator-protocol

* add tracing spans to pov-distribution

* add tracing spans to statement-distribution

* add tracing spans to overseer

* cleanup

* add max_pov_size to runtime config and PersistedValidationData

Closes #1572.

* set default genesis max_pov_size

* apply suggestions from code review

* add default max_pov_size to polkadot_testnet_genesis

We need to distribute the PoV after we have seconded it. Other nodes
that will receive our `Secondded` statement and want to validate the
candidate another time will request this PoV from us.

* Make `CandidateHash` a real type

This pr adds a new type `CandidateHash` that is used instead of the
opaque `Hash` type. This helps to ensure on the type system level that
we are passing the correct types.

This pr also fixes wrong usage of `relay_parent` as `candidate_hash`
when communicating with the av storage.

* Update core-primitives/src/lib.rs

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

* Wrap the lines

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

* utils: remove unused error

* av-store: do not exit early on errors

* av-store: revert logging change on master

* av-store: add a test

* DMP: data structures and plumbing

* DMP: Implement DMP logic in the router module

DMP: Integrate DMP parts into the inclusion module

* DMP: Introduce the max size limit for the size of a downward message

* DMP: Runtime API for accessing inbound messages

* OCD

Small clean ups

* DMP: fix the naming of the error

* DMP: add caution about a non-existent recipient

* Initial commit

* Move tests to separate module

* Move timestamps to the newtype

* Change idx name

* Use Duration for consts and update chunk records

* Ordering::Equal

* Update node/core/av-store/src/lib.rs

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

* put_ methods do the array sorting

* Fix get_block_number

* Change StoreChunk message type and relay parent method

* Add chunk tests

* Fix block number computation for StoreChunk

* Duration instead of u64 everywhere

* Add a clarifying comment

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>