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/src/service/tests.rs

@@ -146,11 +146,11 @@ fn build_test_full_node(
 		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: None,
+		request_response_protocol_configs: Vec::new(),
 	})
 	.unwrap();