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/options.dart

@@ -1,4 +1,4 @@
-import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:flutter_webrtc/flutter_webrtc.dart' as rtc;
 
 enum LocalVideoTrackType {
   camera,
@@ -10,7 +10,7 @@ enum CameraPosition {
   back,
 }
 
-extension LKCameraPositionExt on CameraPosition {
+extension CameraPositionExt on CameraPosition {
   CameraPosition swap() => {
         CameraPosition.front: CameraPosition.back,
         CameraPosition.back: CameraPosition.front,
@@ -74,12 +74,12 @@ class VideoEncoding {
 }
 
 extension VideoEncodingExt on VideoEncoding {
-  RTCRtpEncoding toRTCRtpEncoding({
+  rtc.RTCRtpEncoding toRTCRtpEncoding({
     String? rid,
     double? scaleResolutionDownBy = 1.0,
     int? numTemporalLayers,
   }) =>
-      RTCRtpEncoding(
+      rtc.RTCRtpEncoding(
         rid: rid,
         scaleResolutionDownBy: scaleResolutionDownBy,
         maxFramerate: maxFramerate,