Better audio management (#10)

* add audio_session package

* `AudioManager` initial design

* try to integrate audio manager

* configure audio session

* `DisposeAware`

disposing if already published causes exception.

* organize

* guard flutter_webrtc calls

* websocket async fix

* use `ConnectionState` instead of `_isClosed` and `isReconnecting`

* change create audio track defaults

* update protos

* protocol 3 speaker updates

* fix exception

* emit `RoomDisconnectedEvent` only once

* fix exception

* keep track of local / remote audio tracks

* explicit types

* manage track state

* re-structure audio management

* change defaults

* unpublish all

* use experimental build

* change defaults

* configuring is optional

* call native `RTCAudioSession.setConfiguration`

* defaults adjustment

* iOS only for now

* use lib 92.4515.07

* clean up

* revert audio options for now

* remove pod source

* rename apple related audio

* `createListener` method

* organize native audio

* `SpeakingChangedEvent` only on `Participant`

* refactoring

* fix ios compile

* fix configure audio only for iOS logic

* minor fix & clean up

* change dispose logic

* format protos

* fix unpublishTrack

* `createListener` into a mixin

* simplify

* use flutter_webrtc master

* unpublish for example

* update ios icon

* android icon

* web icon

* favicon

example/lib/widgets/controls.dart

@@ -1,9 +1,10 @@
 import 'dart:convert';
 
+import 'package:collection/collection.dart';
 import 'package:eva_icons_flutter/eva_icons_flutter.dart';
 import 'package:flutter/material.dart';
 import 'package:livekit_client/livekit_client.dart';
-import 'package:collection/collection.dart';
+
 import '../exts.dart';
 
 class ControlsWidget extends StatefulWidget {
@@ -44,6 +45,15 @@ class _ControlsWidgetState extends State<ControlsWidget> {
     setState(() {});
   }
 
+  void _unpublishAll() async {
+    final result = await context.showUnPublishDialog();
+    if (result == true) {
+      await participant.unpublishAllTracks();
+      // Force to update UI for now
+      participant.notifyListeners();
+    }
+  }
+
   void _muteAudio() {
     if (participant.hasAudio) {
       final audioPub = participant.audioTracks.first;
@@ -146,6 +156,10 @@ class _ControlsWidgetState extends State<ControlsWidget> {
     return Row(
       mainAxisAlignment: MainAxisAlignment.center,
       children: [
+        IconButton(
+          onPressed: _unpublishAll,
+          icon: const Icon(EvaIcons.closeCircleOutline),
+        ),
         if (canMute)
           IconButton(
             onPressed: _muteAudio,