Switch to new event system (#9)

* `SignalEvents` and `synchronized` mode for `EventsListenable`

* cascade syntax

* clean up

* `RoomEvents`

* `ParticipantEvents`

* all events implemented

* make it compile with M1 macs

* dispose logic

* cleaner connect logic

* ask to publish

* fix initial EngineTrackAddedEvent glitch

* fix unpublishTrack bug

* clean up

* better events docs

* organize event types

* clean up

* cleaner wait logic

* wait for event instead of using Completer

* notifyListeners

lib/src/track/local_track_publication.dart

@@ -1,4 +1,7 @@
+import '../events.dart';
+import '../extensions.dart';
 import '../logger.dart';
+import '../managers/event.dart';
 import '../participant/local_participant.dart';
 import '../proto/livekit_models.pb.dart' as lk_models;
 import 'track.dart';
@@ -23,15 +26,20 @@ class LocalTrackPublication extends TrackPublication {
 
     super.muted = val;
     track?.mediaStreamTrack.enabled = !val;
-    _participant.engine.client.sendMuteTrack(sid, val);
+    _participant.engine.signalClient.sendMuteTrack(sid, val);
 
     if (val) {
-      _participant.delegate?.onTrackMuted(_participant, this);
-      _participant.roomDelegate?.onTrackMuted(_participant, this);
+      // Track muted
+      [_participant.events, _participant.roomEvents].emit(TrackMutedEvent(
+        participant: _participant,
+        track: this,
+      ));
     } else {
-      _participant.delegate?.onTrackUnmuted(_participant, this);
-      _participant.roomDelegate?.onTrackUnmuted(_participant, this);
+      // Track un-muted
+      [_participant.events, _participant.roomEvents].emit(TrackUnmutedEvent(
+        participant: _participant,
+        track: this,
+      ));
     }
-    _participant.muteChanged();
   }
 }

lib/src/track/remote_track_publication.dart

@@ -1,7 +1,11 @@
+import 'package:livekit_client/livekit_client.dart';
+
 import '../participant/remote_participant.dart';
 import '../proto/livekit_models.pb.dart' as lk_models;
 import '../proto/livekit_rtc.pb.dart' as lk_rtc;
 import 'track.dart';
+import '../extensions.dart';
+
 import 'track_publication.dart';
 
 /// Represents a track publication from a RemoteParticipant. Provides methods to
@@ -50,16 +54,21 @@ class RemoteTrackPublication extends TrackPublication {
     }
     super.muted = val;
     if (val) {
-      _participant.delegate?.onTrackMuted(_participant, this);
-      _participant.roomDelegate?.onTrackMuted(_participant, this);
+      // Track muted
+      [_participant.events, _participant.roomEvents].emit(TrackMutedEvent(
+        participant: _participant,
+        track: this,
+      ));
     } else {
-      _participant.delegate?.onTrackUnmuted(_participant, this);
-      _participant.roomDelegate?.onTrackUnmuted(_participant, this);
+      // Track un-muted
+      [_participant.events, _participant.roomEvents].emit(TrackUnmutedEvent(
+        participant: _participant,
+        track: this,
+      ));
     }
     if (subscribed) {
       track?.mediaStreamTrack.enabled = !val;
     }
-    _participant.muteChanged();
   }
 
   RemoteTrackPublication(

lib/src/track/track.dart

@@ -1,28 +1,29 @@
 import 'package:flutter_webrtc/flutter_webrtc.dart' as rtc;
+import 'package:livekit_client/src/classes/change_notifier.dart';
 import 'package:uuid/uuid.dart';
 
 import '../proto/livekit_models.pb.dart' as lk_models;
 
-class TrackDimension {
-  int width;
-  int height;
-
-  TrackDimension(this.width, this.height);
-}
-
 /// Wrapper around a MediaStreamTrack with additional metadata.
-class Track {
+/// Base for [AudioTrack] and [VideoTrack],
+/// can not be instantiated directly.
+abstract class Track extends LKChangeNotifier {
   static const cameraName = 'camera';
   static const screenShareName = 'screen';
 
-  String name;
-  lk_models.TrackType kind;
+  final String name;
+  final lk_models.TrackType kind;
   rtc.MediaStreamTrack mediaStreamTrack;
+
   String? sid;
   rtc.RTCRtpTransceiver? transceiver;
   String? _cid;
 
-  Track(this.kind, this.name, this.mediaStreamTrack);
+  Track(
+    this.kind,
+    this.name,
+    this.mediaStreamTrack,
+  );
 
   bool get muted => mediaStreamTrack.muted == null ? false : mediaStreamTrack.muted!;
 

lib/src/track/track_publication.dart

@@ -1,13 +1,19 @@
 import '../proto/livekit_models.pb.dart' as lk_models;
+import '../types.dart';
 import 'track.dart';
 
 /// Represents a track that's published to the server. This class contains
 /// metadata associated with tracks.
-class TrackPublication {
+///
+/// Base for [RemoteTrackPublication] and [LocalTrackPublication],
+/// can not be instantiated directly.
+
+abstract class TrackPublication {
+  final String name;
+  final String sid;
+  final lk_models.TrackType kind;
+
   Track? track;
-  String name;
-  String sid;
-  lk_models.TrackType kind;
   bool muted = false;
   bool simulcasted = false;
   TrackDimension? dimension;
@@ -31,4 +37,12 @@ class TrackPublication {
       dimension = TrackDimension(info.width, info.height);
     }
   }
+
+  // Equality operators
+  // Object is considered equal when sid is equal
+  @override
+  int get hashCode => sid.hashCode;
+
+  @override
+  bool operator ==(Object other) => other is TrackPublication && sid == other.sid;
 }

lib/src/track/video_track.dart

@@ -1,12 +1,10 @@
-import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
 import 'package:flutter_webrtc/flutter_webrtc.dart' as rtc;
 
 import '../proto/livekit_models.pb.dart' as lk_models;
 import 'track.dart';
 
 /// A video track will notify when its mediaTrack has changed.
-class VideoTrack extends Track with ChangeNotifier {
+class VideoTrack extends Track {
   rtc.MediaStream _mediaStream;
 
   VideoTrack(