Rustify core/src/core (#1122)

Small refactoring of one folder, if it makes sense I could extend the scope.
* Remove some cloning (real and just verbosity in the code)
* Naming conventions like to/into*
* Some Clippy's suggestions

I found that we don't use field init shorthand syntax, so I didn't touch this part, was it discussed before?

p2p/tests/peer_handshake.rs

@@ -61,7 +61,7 @@ fn peer_handshake() {
 			p2p_config.clone(),
 			dandelion_config.clone(),
 			net_adapter.clone(),
-			Hash::from_vec(vec![]),
+			Hash::from_vec(&vec![]),
 			Arc::new(AtomicBool::new(false)),
 			false,
 			None,
@@ -82,7 +82,7 @@ fn peer_handshake() {
 		p2p::Capabilities::UNKNOWN,
 		Difficulty::one(),
 		my_addr,
-		&p2p::handshake::Handshake::new(Hash::from_vec(vec![]), p2p_config.clone()),
+		&p2p::handshake::Handshake::new(Hash::from_vec(&vec![]), p2p_config.clone()),
 		net_adapter,
 	).unwrap();