Prepare for network protocol version upgrades (#5084)

* explicitly tag network requests with version

* fmt

* make PeerSet more aware of versioning

* some generalization of the network bridge to support upgrades

* walk back some renaming

* walk back some version stuff

* extract version from fallback

* remove V1 from NetworkBridgeUpdate

* add accidentally-removed timer

* implement focusing for versioned messages

* fmt

* fix up network bridge & tests

* remove inaccurate version check in bridge

* remove some TODO [now]s

* fix fallout in statement distribution

* fmt

* fallout in gossip-support

* fix fallout in collator-protocol

* fix fallout in bitfield-distribution

* fix fallout in approval-distribution

* fmt

* use never!

* fmt

polkadot/node/network/availability-distribution/src/requester/fetch_task/mod.rs

@@ -330,7 +330,7 @@ impl RunningTask {
 	) -> std::result::Result<ChunkFetchingResponse, TaskError> {
 		let (full_request, response_recv) =
 			OutgoingRequest::new(Recipient::Authority(validator.clone()), self.request);
-		let requests = Requests::ChunkFetching(full_request);
+		let requests = Requests::ChunkFetchingV1(full_request);
 
 		self.sender
 			.send(FromFetchTask::Message(AllMessages::NetworkBridge(

polkadot/node/network/availability-distribution/src/requester/fetch_task/tests.rs

@@ -235,7 +235,7 @@ impl TestRun {
 				let mut valid_responses = 0;
 				for req in reqs {
 					let req = match req {
-						Requests::ChunkFetching(req) => req,
+						Requests::ChunkFetchingV1(req) => req,
 						_ => panic!("Unexpected request"),
 					};
 					let response =