cmd/lncli: properly reverse user txid input

This commit fixes a bug introduced within a prior commit. The prior
commit failed to drollery reverse the txid string taken in as user
input, therefore in order to properly close a channel, the user needed
to manually reverse the txid themselves.

With this change, `wire.NewShaHashFromStr` is used which properly
reverses the string within the constructor. This allows the string
reported not be directly used to the close an active channel.

This commit also corrects a few logging messages.

rpcserver.go

@@ -171,7 +171,7 @@ func (r *rpcServer) OpenChannel(ctx context.Context,
 		return nil, err
 	}
 
-	rpcsLog.Tracef("Opened channel with peerid(%v), fundingtxid %v",
+	rpcsLog.Tracef("Opened channel with peerid(%v), ChannelPoint(%v)",
 		in.TargetPeerId, resp)
 
 	return &lnrpc.OpenChannelResponse{