fundingmanager: change funding messages to use server.sendToPeer

Previously, during the channel funding process, peers sent wire
messages using peer.queueMsg. By switching to server.sendToPeer, the
fundingManager is more resilient to network connection issues or system
restarts during the funding process. With server.sendToPeer, if a peer
gets disconnected, the daemon can attempt to reconnect and continue the
process using the peer’s public key ID.

rpcserver.go

@@ -770,7 +770,6 @@ func (r *rpcServer) PendingChannels(ctx context.Context,
 			// TODO(roasbeef): add confirmation progress
 			pub := pendingOpen.identityPub.SerializeCompressed()
 			pendingChan := &lnrpc.PendingChannelResponse_PendingChannel{
-				PeerId:        pendingOpen.peerId,
 				IdentityKey:   hex.EncodeToString(pub),
 				ChannelPoint:  channelPointStr,
 				Capacity:      int64(pendingOpen.capacity),