Move bitswap to its own crate (#12242)

* Introduce `sc-network-bitswap`

Move the bitswap protocol out of `sc-network` to its own crate.

* Improve test coverage

* Remove mention of bitswap from `sc-network`

* Fix documentation

* Fix clippy and remove the void dependency

* Remove unneeded trait bound and bump prost to 0.11

substrate/client/network/test/src/lib.rs

@@ -883,11 +883,11 @@ where
 			import_queue,
 			chain_sync: Box::new(chain_sync),
 			metrics_registry: None,
-			bitswap: None,
 			block_request_protocol_config,
 			state_request_protocol_config,
 			light_client_request_protocol_config,
 			warp_sync_protocol_config: Some(warp_protocol_config),
+			request_response_protocol_configs: Vec::new(),
 		})
 		.unwrap();