multi: add labels to lnd native transactions

Follow up labelling of external transactions with labels for the
transaction types we create within lnd. Since these labels will live
a life of string matching, a version number and rigid format is added
so that string matching is less painful. We start out with channel ID,
where available, and a transaction "type". External labels, added in a
previous PR, are not updated to this new versioned label because they
are not lnd-initiated transactions. Label matching can check this case,
then check for a version number.

breacharbiter.go

@@ -20,6 +20,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb/kvdb"
 	"github.com/lightningnetwork/lnd/htlcswitch"
 	"github.com/lightningnetwork/lnd/input"
+	"github.com/lightningnetwork/lnd/labels"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 )
@@ -566,7 +567,8 @@ justiceTxBroadcast:
 
 	// We'll now attempt to broadcast the transaction which finalized the
 	// channel's retribution against the cheating counter party.
-	err = b.cfg.PublishTransaction(finalTx, "")
+	label := labels.MakeLabel(labels.LabelTypeJusticeTransaction, nil)
+	err = b.cfg.PublishTransaction(finalTx, label)
 	if err != nil {
 		brarLog.Errorf("Unable to broadcast justice tx: %v", err)