Organize events (#13)

* move internal events & remove unused events

* `TrackUnpublishedEvent` for local tracks

* update example since we have local track unpublish events

* use flutter_webrtc 0.6.9

lib/src/participant/local_participant.dart

@@ -151,14 +151,11 @@ class LocalParticipant extends Participant {
 
   /// Unpublish a track that's already published
   @override
-  Future<void> unpublishTrack(String trackSid, {bool notify = false}) async {
+  Future<void> unpublishTrack(String trackSid, {bool notify = true}) async {
     logger.finer('Unpublish track sid: $trackSid, notify: $notify');
     final pub = trackPublications.remove(trackSid);
     if (pub is! LocalTrackPublication) return;
 
-    // final existing = tracks.values.where((element) => element.track == track);
-    // if (existing.isEmpty) return;
-    // final pub = existing.first;
     final track = pub.track;
     if (track != null) {
       await track.stop();
@@ -178,6 +175,13 @@ class LocalParticipant extends Participant {
         }
       }
     }
+
+    if (notify) {
+      [events, roomEvents].emit(TrackUnpublishedEvent(
+        participant: this,
+        publication: pub,
+      ));
+    }
   }
 
   /// Publish a new data payload to the room.

lib/src/participant/remote_participant.dart

@@ -152,7 +152,7 @@ class RemoteParticipant extends Participant {
   }
 
   @override
-  Future<void> unpublishTrack(String trackSid, {bool notify = false}) async {
+  Future<void> unpublishTrack(String trackSid, {bool notify = true}) async {
     logger.finer('Unpublish track sid: $trackSid, notify: $notify');
     final pub = trackPublications.remove(trackSid);
     if (pub is! RemoteTrackPublication) return;
@@ -166,10 +166,6 @@ class RemoteParticipant extends Participant {
         track: track,
         publication: pub,
       ));
-
-      // if (track is AudioTrack) {
-      //   await AudioManager().decrementSubscriptionCounter();
-      // }
     }
 
     if (notify) {