Match muted behavior with JS SDK (#32)

* attempt 1

* implement

* clean up

* clean up

* cleaner code

* mute was opposite

* fix suggestion

* fix local pub muted

* update example

* update pubs

* format

lib/src/track/track.dart

@@ -33,6 +33,9 @@ abstract class Track extends DisposableChangeNotifier
   bool _active = false;
   bool get isActive => _active;
 
+  bool _muted = false;
+  bool get muted => _muted;
+
   Track(
     this.kind,
     this.source,
@@ -52,9 +55,6 @@ abstract class Track extends DisposableChangeNotifier
     });
   }
 
-  bool get muted =>
-      mediaStreamTrack.muted == null ? false : mediaStreamTrack.muted!;
-
   rtc.RTCRtpMediaType get mediaType {
     switch (kind) {
       case lk_models.TrackType.AUDIO:
@@ -125,4 +125,7 @@ abstract class Track extends DisposableChangeNotifier
           '[$objectId] set rtc.mediaStreamTrack.enabled did throw ${_}');
     }
   }
+
+  @internal
+  void updateMuted(bool muted) => _muted = muted;
 }