Clean up sc-network (#9761)

* Clean up sc-network

- Avoid using clone() for the Copy type `PeerId`.
- Use `find_map` for `filter_map` and `next`.
- Use `Self`.

* More on Copy types

* Cargo +nightly fmt --all

* More ..

* fmt

* Revert vec![default_notif_handshake_message]

substrate/client/authority-discovery/src/worker/addr_cache.rs

@@ -199,7 +199,7 @@ mod tests {
 			let multiaddr1 = "/ip6/2001:db8:0:0:0:0:0:2/tcp/30333"
 				.parse::<Multiaddr>()
 				.unwrap()
-				.with(Protocol::P2p(peer_id.clone().into()));
+				.with(Protocol::P2p(peer_id.into()));
 			let multiaddr2 = "/ip6/2002:db8:0:0:0:0:0:2/tcp/30133"
 				.parse::<Multiaddr>()
 				.unwrap()