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/track/audio_track.dart

@@ -1,4 +1,4 @@
-import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:flutter_webrtc/flutter_webrtc.dart' as rtc;
 
 import '../proto/livekit_models.pb.dart' as lk_models;
 import '_audio_api.dart' if (dart.library.html) '_audio_html.dart' as audio;
@@ -6,9 +6,9 @@ import 'local_audio_track.dart';
 import 'track.dart';
 
 class AudioTrack extends Track {
-  MediaStream? mediaStream;
+  rtc.MediaStream? mediaStream;
 
-  AudioTrack(String name, MediaStreamTrack track, this.mediaStream)
+  AudioTrack(String name, rtc.MediaStreamTrack track, this.mediaStream)
       : super(lk_models.TrackType.AUDIO, name, track);
 
   /// Start playing audio track. On web platform, create an audio element and