* 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 !