lnrpc: move initiator enum out of close summary

Move enum out of CloseSummary struct for more general use. This does
not change the encoding of the enum, and will only cause compile time
errors for existing clients. This enum has not been included in a
release yet, so we can make this move without much disruption.

rpcserver.go

@@ -3370,8 +3370,8 @@ func (r *rpcServer) createRPCClosedChannel(
 
 	var (
 		closeType      lnrpc.ChannelCloseSummary_ClosureType
-		openInit       lnrpc.ChannelCloseSummary_Initiator
-		closeInitiator lnrpc.ChannelCloseSummary_Initiator
+		openInit       lnrpc.Initiator
+		closeInitiator lnrpc.Initiator
 		err            error
 	)
 
@@ -3422,12 +3422,12 @@ func (r *rpcServer) createRPCClosedChannel(
 // channel is not present (which indicates that it was closed before we started
 // writing channels to the historical close bucket).
 func (r *rpcServer) getInitiators(chanPoint *wire.OutPoint) (
-	lnrpc.ChannelCloseSummary_Initiator,
-	lnrpc.ChannelCloseSummary_Initiator, error) {
+	lnrpc.Initiator,
+	lnrpc.Initiator, error) {
 
 	var (
-		openInitiator  = lnrpc.ChannelCloseSummary_UNKNOWN
-		closeInitiator = lnrpc.ChannelCloseSummary_UNKNOWN
+		openInitiator  = lnrpc.Initiator_INITIATOR_UNKNOWN
+		closeInitiator = lnrpc.Initiator_INITIATOR_UNKNOWN
 	)
 
 	// To get the close initiator for cooperative closes, we need
@@ -3452,9 +3452,9 @@ func (r *rpcServer) getInitiators(chanPoint *wire.OutPoint) (
 	// If we successfully looked up the channel, determine initiator based
 	// on channels status.
 	if histChan.IsInitiator {
-		openInitiator = lnrpc.ChannelCloseSummary_LOCAL
+		openInitiator = lnrpc.Initiator_INITIATOR_LOCAL
 	} else {
-		openInitiator = lnrpc.ChannelCloseSummary_REMOTE
+		openInitiator = lnrpc.Initiator_INITIATOR_REMOTE
 	}
 
 	localInit := histChan.HasChanStatus(
@@ -3470,13 +3470,13 @@ func (r *rpcServer) getInitiators(chanPoint *wire.OutPoint) (
 	// We return the initiator as both in this case to provide full
 	// information about the close.
 	case localInit && remoteInit:
-		closeInitiator = lnrpc.ChannelCloseSummary_BOTH
+		closeInitiator = lnrpc.Initiator_INITIATOR_BOTH
 
 	case localInit:
-		closeInitiator = lnrpc.ChannelCloseSummary_LOCAL
+		closeInitiator = lnrpc.Initiator_INITIATOR_LOCAL
 
 	case remoteInit:
-		closeInitiator = lnrpc.ChannelCloseSummary_REMOTE
+		closeInitiator = lnrpc.Initiator_INITIATOR_REMOTE
 	}
 
 	return openInitiator, closeInitiator, nil