Consistently use wire::Message for encoding network messages

Previously, `enqueue_message` took an `M: Type + Writeable` reference,
which didn't make use of our `wire::Message` type, which turned out to
be rather confusing. Here, we use `Message` consistently in
`PeerManager`'s `enqueue_message`, but also in `encrypt_message`, etc.

While at it we also switch to move semantics, which is a nice cleanup.

Author: tnull

lightning/src/ln/channelmanager.rs

@@ -13872,7 +13872,9 @@ where
 							&MessageSendEvent::UpdateHTLCs { .. } => false,
 							&MessageSendEvent::SendRevokeAndACK { .. } => false,
 							&MessageSendEvent::SendClosingSigned { .. } => false,
+							#[cfg(simple_close)]
 							&MessageSendEvent::SendClosingComplete { .. } => false,
+							#[cfg(simple_close)]
 							&MessageSendEvent::SendClosingSig { .. } => false,
 							&MessageSendEvent::SendShutdown { .. } => false,
 							&MessageSendEvent::SendChannelReestablish { .. } => false,

lightning/src/ln/functional_test_utils.rs

@@ -1124,7 +1124,9 @@ pub fn remove_first_msg_event_to_node(
 		MessageSendEvent::UpdateHTLCs { node_id, .. } => node_id == msg_node_id,
 		MessageSendEvent::SendRevokeAndACK { node_id, .. } => node_id == msg_node_id,
 		MessageSendEvent::SendClosingSigned { node_id, .. } => node_id == msg_node_id,
+		#[cfg(simple_close)]
 		MessageSendEvent::SendClosingComplete { node_id, .. } => node_id == msg_node_id,
+		#[cfg(simple_close)]
 		MessageSendEvent::SendClosingSig { node_id, .. } => node_id == msg_node_id,
 		MessageSendEvent::SendShutdown { node_id, .. } => node_id == msg_node_id,
 		MessageSendEvent::SendChannelReestablish { node_id, .. } => node_id == msg_node_id,

lightning/src/ln/msgs.rs

@@ -1857,13 +1857,15 @@ pub enum MessageSendEvent {
 		msg: ClosingSigned,
 	},
 	/// Used to indicate that a `closing_complete` message should be sent to the peer with the given `node_id`.
+	#[cfg(simple_close)]
 	SendClosingComplete {
 		/// The node_id of the node which should receive this message
 		node_id: PublicKey,
 		/// The message which should be sent.
 		msg: ClosingComplete,
 	},
 	/// Used to indicate that a `closing_sig` message should be sent to the peer with the given `node_id`.
+	#[cfg(simple_close)]
 	SendClosingSig {
 		/// The node_id of the node which should receive this message
 		node_id: PublicKey,

lightning/src/ln/peer_channel_encryptor.rs

@@ -565,12 +565,12 @@ impl PeerChannelEncryptor {
 	/// Encrypts the given message, returning the encrypted version.
 	/// panics if the length of `message`, once encoded, is greater than 65535 or if the Noise
 	/// handshake has not finished.
-	pub fn encrypt_message<M: wire::Type>(&mut self, message: &M) -> Vec<u8> {
+	pub fn encrypt_message<T: wire::Type>(&mut self, message: wire::Message<T>) -> Vec<u8> {
 		// Allocate a buffer with 2KB, fitting most common messages. Reserve the first 16+2 bytes
 		// for the 2-byte message type prefix and its MAC.
 		let mut res = VecWriter(Vec::with_capacity(MSG_BUF_ALLOC_SIZE));
 		res.0.resize(16 + 2, 0);
-		wire::write(message, &mut res).expect("In-memory messages must never fail to serialize");
+		wire::write(&message, &mut res).expect("In-memory messages must never fail to serialize");
 
 		self.encrypt_message_with_header_0s(&mut res.0);
 		res.0