Simulcast, Screen sharing & Various improvements (#4)

* Respect `RTCIceTransportPolicy` enum and organize

* Simplify syntax where possible etc.

* Combine `VideoPreset` and `VideoPresets`

* Default values for `ConnectOptions`

* Build URI instead of String manipulation

* Slight modifications to Exception

* `LiveKitTheme` for example

* `VideoEncoding` class

* Organize imports

* First simulcast implementation

* Remove unnecessary try-catches

* Update Android settings

* Remember uri and token

* example improvements

* `fit` parameter for VideoTrackRenderer

* Simulcast option for example

* Pass `defaultPublishOptions`

* Show only `VideoQuality`

* Pass tests

* Better buildUri logic

* Named parameter to positional

* Explicit imports

* `VideoParameter` instead of `VideoPreset`

* Use `mediaTrack.getSettings` when possible

* Safer dispose logic

* Safer `PCTransport`

Update transport.dart

* Synchronized events for `SignalClient`

* Use logger instead of print

* Make example compile for iOS

* First screen share implementation

* Make example work with screen share

* Example improvement

* Code optimization

* Don't depend on web_socket_channel

* Fix: Unpublish track bug

* Show participant mute state & identity

* Update protos

* Remote mute/unmute

* iOS Background mode

* Separate `createCameraTrack` and `createScreenTrack`

* Clean up

* PB fix

* format

* Fix analyzer warning

* Android clean up

* Update README.md

* Clean up

lib/src/livekit.dart

@@ -1,12 +1,22 @@
-import 'room.dart';
 import 'options.dart';
+import 'room.dart';
 
 /// Main entry point to connect to a room.
 /// {@category Room}
 class LiveKitClient {
+  static const version = '0.4.0';
+
   /// Connects to a LiveKit room
-  static Future<Room> connect(String url, String token, [JoinOptions? options]) {
+  static Future<Room> connect(
+    String url,
+    String token, {
+    ConnectOptions? options,
+  }) {
     final room = Room();
-    return room.connect(url, token, options);
+    return room.connect(
+      url,
+      token,
+      options: options,
+    );
   }
 }