dispute-coordinator: past session dispute slashing (#6811)

* runtime/vstaging: unapplied_slashes runtime API

* runtime/vstaging: key_ownership_proof runtime API

* runtime/ParachainHost: submit_report_dispute_lost

* fix key_ownership_proof API

* runtime: submit_report_dispute_lost runtime API

* nits

* Update node/subsystem-types/src/messages.rs

Co-authored-by: Marcin S. <marcin@bytedude.com>

* revert unrelated fmt changes

* dispute-coordinator: past session dispute slashing

* encapsule runtime api call for submitting report

* prettify: extract into a function

* do not exit on runtime api error

* fix tests

* try initial zombienet test

* try something

* fix a typo

* try cumulus-based collator

* fix clippy

* build polkadot-debug images with fast-runtime enabled

* wip

* runtime/inclusion: fix availability_threshold

* fix wip

* fix wip II

* revert native provider

* propagate tx submission error

* DEBUG: sync=trace

* print key ownership proof len

* panic repro

* log validator index in panic message

* post merge fixes

* replace debug assertion with a log

* fix compilation

* Let's log the dispatch info in validate block.

* fix double encoding

* Revert "Let's log the dispatch info in validate block."

This reverts commit a70fbc51b464d7f4355dbada5e16cd83cf71eab4.

* Revert "Let's log the dispatch info in validate block."

This reverts commit a70fbc51b464d7f4355dbada5e16cd83cf71eab4.

* fix compilation

* update to latest zombienet and fix test

* lower finality lag to 11

* bump zombienet again

* add a workaround, but still does not work

* Update .gitlab-ci.yml

bump zombienet.

* add a comment and search logs on all nodes

---------

Co-authored-by: Marcin S. <marcin@bytedude.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: Javier Viola <javier@parity.io>

polkadot/primitives/src/vstaging/slashing.rs

@@ -96,4 +96,9 @@ impl OpaqueKeyOwnershipProof {
 	pub fn decode<T: Decode>(self) -> Option<T> {
 		Decode::decode(&mut &self.0[..]).ok()
 	}
+
+	/// Length of the encoded proof.
+	pub fn len(&self) -> usize {
+		self.0.len()
+	}
 }