Update to libp2p-0.23. (#6870)

* Update to libp2p-0.23.

Thereby incorporate bandwidth measurement along the
lines previously done by libp2p itself.

* Tweak dependencies for wasm32 compilation.

For wasm32 we need to enable unstable features to
make `task::Builder::local` available.

* Simplify dependencies.

* Simplify.

Leave the calculation of bytes sent/received per second
to the outer layers of the code, subject to their own
individual update intervals.

* Cleanup

* Re-add lost dev dependency.

* Avoid division by zero.

* Remove redundant metric.

* Enable sending of noise legacy handshakes.

* Add comment about monotonic gauge.

* CI

substrate/client/rpc/src/system/tests.rs

@@ -87,8 +87,8 @@ fn api<T: Into<Option<Status>>>(sync: T) -> System<Block> {
 						external_addresses: Default::default(),
 						connected_peers: Default::default(),
 						not_connected_peers: Default::default(),
-						average_download_per_sec: 0,
-						average_upload_per_sec: 0,
+						total_bytes_inbound: 0,
+						total_bytes_outbound: 0,
 						peerset: serde_json::Value::Null,
 					}).unwrap());
 				},
@@ -282,8 +282,8 @@ fn system_network_state() {
 			external_addresses: Default::default(),
 			connected_peers: Default::default(),
 			not_connected_peers: Default::default(),
-			average_download_per_sec: 0,
-			average_upload_per_sec: 0,
+			total_bytes_inbound: 0,
+			total_bytes_outbound: 0,
 			peerset: serde_json::Value::Null,
 		}
 	);