Allow to broadcast network messages in parallel (#1409)

This PR addresses multiple issues pending:

* [x] Update orchestra to the recent version and test how the node
performs
* [x] Add some useful metrics for outbound network bridge
* [x] Try to send incoming network requests to all subsystems without
blocking on some particular subsystem in that loop
* [x] Fix all incompatibilities between orchestra and polkadot code
(e.g. malus node)

polkadot/node/subsystem-test-helpers/src/lib.rs

@@ -20,7 +20,7 @@
 
 use polkadot_node_subsystem::{
 	messages::AllMessages, overseer, FromOrchestra, OverseerSignal, SpawnGlue, SpawnedSubsystem,
-	SubsystemError, SubsystemResult,
+	SubsystemError, SubsystemResult, TrySendError,
 };
 use polkadot_node_subsystem_util::TimeoutExt;
 
@@ -160,6 +160,14 @@ where
 		self.tx.send(msg.into()).await.expect("test overseer no longer live");
 	}
 
+	fn try_send_message(
+		&mut self,
+		msg: OutgoingMessage,
+	) -> Result<(), TrySendError<OutgoingMessage>> {
+		self.tx.unbounded_send(msg.into()).expect("test overseer no longer live");
+		Ok(())
+	}
+
 	async fn send_messages<I>(&mut self, msgs: I)
 	where
 		I: IntoIterator<Item = OutgoingMessage> + Send,