* Notify collators about seconded collation
This pr adds functionality to inform a collator that its collation was
seconded by a parachain validator. Before this signed statement was only
gossiped over the validation substream. Now, we explicitly send the
seconded statement to the collator after it was validated successfully.
Besides that it changes the `CollatorFn` to return an optional result
sender that is informed when the build collation was seconded by a
parachain validator.
* Add test
* Make sure we only send `Seconded` statements
* Make sure we only receive valid statements
* Review feedback
* 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
* Do not validate a candidate in candidate selection
The candidate selection subsystem should not validate a candidate, as
this is done by the backing subsystem on a `Second` request. Otherwise
we validate one candidate twice.
* Update candidate-selection.md
* choose the straightforward candidate selection algorithm for now
* add draft implementation of candidate selection
* fix typo in summary
* more properly report misbehaving collators
* describe how CandidateSelection subsystem becomes aware of candidates
* revise candidate selection / collator protocol interaction pattern
* implement rest of candidate selection per the guide
* review: resolve nits
* start writing test suite, harness
* implement first test
* add second test
* implement third test
Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>
Robert Habermeier