Subscriber as primary (#8)

* Update protos

* Signal client

* Improve transport

* First implementation

* Fix publish

* Update `PCTransport` for debounce negotiation

* debounce func

* reconnect & events

* Update debounce func

* engine events

* make sure events don't emit after dispose

* prefix flutter_webrtc

* Cleaner `iceServers` update

* don't mutate user provided params

* fix tests

* event manager

* Fix: `Room.onDisconnected` gets fired multiple times

* data publish in example

* cleaner logic

* safer events

* un-prefix with LK

* organize imports

* Clean up

* remove `Tuple`

* `EventsEmitter` can now be directly listened to

`EventsEmitter` extends `EventsListenable`

lib/src/participant/participant.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/foundation.dart';
 
+import '../events.dart';
+import '../managers/event.dart';
 import '../proto/livekit_models.pb.dart' as lk_models;
 import '../track/remote_track_publication.dart';
 import '../track/track.dart';
@@ -77,6 +79,9 @@ class Participant extends ChangeNotifier {
   lk_models.ParticipantInfo? _participantInfo;
   bool _isSpeaking = false;
 
+  // suppport for multiple event listeners
+  final events = EventsEmitter<ParticipantEvent>();
+
   /// when the participant joined the room
   DateTime get joinedAt {
     final pi = _participantInfo;
@@ -159,7 +164,7 @@ class Participant extends ChangeNotifier {
 }
 
 // Convenience extension
-extension LKParticipantExt on Participant {
+extension ParticipantExt on Participant {
   List<TrackPublication> get videoTracks =>
       tracks.values.where((e) => e.kind == lk_models.TrackType.VIDEO).toList();