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/ios/Podfile

@@ -44,6 +44,10 @@ post_install do |installer|
     #
     target.build_configurations.each do |config|
       config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.1'
+      #
+      # Make it compile with M1 macs
+      #
+      config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = 'arm64'
     end
 
   end