e2e: fix resume/full-reconnect. (#194)

* fix: full re-connect.

* chore: Reset fullReConnect state after ConnectionState is emitted.

* Support full reconnect, fix Migration, NodeFailure, FullReconnect test cases.

* revert Timeouts.connection.

* update.

* Refactor the resume/reconnect implementation.

* more changes.

* update.

* Changed to simpler reconnect/recovery logic.

* update.

* update.

* code format.

* tidy.

* bump version for flutter-webrtc.

* chore: Remove unused exception class (SignalReconnectError).

* chore: rename `fullReconnectOnNext` to `fullReconnect`.

* update.

* chore: Revert changes for `unpublishTrack`.

* chore: Reconnect signalClient when resumeConnection.

* revert `rethrow` in engine.connect.

* Use removePublishedTrack instead of unpublishTrack (RemoteParticipant).

* chore: Correctly handle PeerConnectionState for resume/full-reconnect.

* tidy.

lib/src/core/signal_client.dart

@@ -35,6 +35,10 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
   Duration? _pingIntervalDuration;
   Timer? _pingIntervalTimer;
 
+  int get pingCount => _pingCount;
+
+  int _pingCount = 0;
+
   @internal
   SignalClient(WebSocketConnector wsConnector) : _wsConnector = wsConnector {
     events.listen((event) {
@@ -240,6 +244,7 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
         logger.info('signal message not set');
         break;
       case lk_rtc.SignalResponse_Message.pong:
+        _pingCount++;
         _resetPingTimeout();
         break;
       default: