fundingmanager: populate additional edge info after adding to graph

This commit serves as another stop-gap for light clients since they are
unable to obtain the capacity and channel point of graph edges. Since
they're aware of these things for their own channels, they can populate
the information within the graph themselves once each channel has been
successfully added to the graph.

server.go

@@ -880,9 +880,11 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB, cc *chainControl,
 		CurrentNodeAnnouncement: func() (lnwire.NodeAnnouncement, error) {
 			return s.genNodeAnnouncement(true)
 		},
-		SendAnnouncement: func(msg lnwire.Message) chan error {
+		SendAnnouncement: func(msg lnwire.Message,
+			optionalFields ...discovery.OptionalMsgField) chan error {
+
 			return s.authGossiper.ProcessLocalAnnouncement(
-				msg, privKey.PubKey(),
+				msg, privKey.PubKey(), optionalFields...,
 			)
 		},
 		NotifyWhenOnline: s.NotifyWhenOnline,