* add pov-block gossip message to network

* tests for pov-block gossip

* integrate pov-block gossip into main protocol

* message validation fetches pov blocks

* remove stray dbg! invocation

* test that pov-block is fetched from relay-parent topic

* Adds a SigningContext type

* Bump spec versions

* Fixes requested changes

* Bump ParachainHost api_version and guard signing_context call

* Improve error message

* If there is no signing_context api use default value

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

* expunge legacy code from polkadot-network

* mostly rip out old legacy protocol from service

* ensure validation work is spawned by incoming messages

* decouple availabliity store from network logic; clean up data flow

* av_store: test helpers and use futures-abort

* update polkadot-validation to pass n_validators when submitting chunks

* fallible erasure-chunk fetching

* implement `ErasureNetworking` for new network prot

* API for registering availability store in network

* fully integrate new network service into service

* fix validation tests

* scaffolding for porting collator over to new network

* track connected validators' peer IDs and distribute collators' collations

* helper in network for fetching all checked statements

* fix adder-collator

* actually register notifications protocol

* Update service/src/lib.rs

* merge with master

* WIP

* WIp

* Mostly get tests to compile

* Fix adder collator

* Remove more stuff

* Revert some changes to av store

* Fix av store tests

* Nitpicks

* Restore some things

* Small changes

* Remvoe unused error variants

* extract all network code to legacy submodule

* update references to legacy proto

* skeleton of futures-based protocol

* refactor skeleton to use background task

* rename communication_for to build_table_router

* implement internal message types for validation network

* basic ParachainNetwork and TableRouter implementations

* add some module docs

* remove exit-future from validation

* hack: adapt legacy protocol to lack of exit-future

* generalize RegisteredMessageValidator somewhat

* instantiate and teardown table routers

* clean up RouterInner drop logic

* implement most of the statement import loop

* implement statement loop in async/await

* remove unneeded TODO

* most of the collation skeleton

* send session keys and validator roles

* also send role after status

* use config in startup

* point TODO to issue

* fix test compilation

* Propagate Substrate#4284 to Polkadot

* Fix tests

* Fixes

* Use hash part of fund id as child unique id.

* Add comma

* Switch branch

* run cargo update

* Update polkadot-master only

* Fix collator

* Reputation changes require reason

* Fixes

* Bump version

* rename crates as appropriate

* Rename to use master - easy to revert, but shows it's working

* Bump runtime version

* Bump version

* Bump Substrate again

* core logic for ICMP gossip

* refactor gossip to make more extension friendly

* move files aroun

* extract attestation-gossip logic to its own module

* message validation and broadcast logic

* fix upstream crates' compilation

* add a test

* another test for overlapping

* Some grammar and phrasing tweaks

Co-Authored-By: Luke Schoen <ltfschoen@users.noreply.github.com>

* add since parameter to ingress runtime API

* broadcast out known unrouted message queues

* fix compilation of service and collator

* remove useless index_mapping

* some tests for icmp propagation

* fix decoding bug and test icmp queue validation

* simplify engine-id definition

Co-Authored-By: Sergei Pepyakin <sergei@parity.io>

* address some grumbles

* some cleanup of old circulation code

* give network a handle to extrinsic store on startup

* an honest collator ensures data available as well

* address some grumbles

* add docs; rename the attestation session to "leaf work"

* module docs

* move gossip back to gossip.rs

* clean up and document attestation-gossip a bit

* some more docs on the availability store

* store all outgoing message queues in the availability store

* filter `Extrinsic` out of validation crate

* expunge Extrinsic from network

* expunge Extrinsic from erasure-coding

* expunge Extrinsic from collator

* expunge from adder-collator

* rename ExtrinsicStore to AvailabilityStore everywhere

* annotate and clean up message-routing tests