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

example/lib/exts.dart

@@ -2,6 +2,24 @@ import 'package:flutter/material.dart';
 
 extension LKExampleExt on BuildContext {
   //
+  Future<bool?> showPublishDialog() => showDialog<bool>(
+        context: this,
+        builder: (ctx) => AlertDialog(
+          title: const Text('Publish'),
+          content: const Text('Would you like to publish your Camera & Mic ?'),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.pop(ctx, false),
+              child: const Text('NO'),
+            ),
+            TextButton(
+              onPressed: () => Navigator.pop(ctx, true),
+              child: const Text('YES'),
+            ),
+          ],
+        ),
+      );
+
   Future<void> showErrorDialog(dynamic exception) => showDialog<void>(
         context: this,
         builder: (ctx) => AlertDialog(
@@ -74,7 +92,7 @@ extension LKExampleExt on BuildContext {
         context: this,
         builder: (ctx) => AlertDialog(
           title: const Text('Received data'),
-          content: Text('"${data}"'),
+          content: Text(data),
           actions: [
             TextButton(
               onPressed: () => Navigator.pop(ctx, true),