TF-3157 Implement web socket push

lib/features/push_notification/domain/state/web_socket_push_state.dart

@@ -0,0 +1,19 @@
+import 'package:core/presentation/state/failure.dart';
+import 'package:core/presentation/state/success.dart';
+import 'package:jmap_dart_client/jmap/push/state_change.dart';
+
+class InitializingWebSocketPushChannel extends LoadingState {}
+
+class WebSocketPushStateReceived extends UIState {
+  final StateChange stateChange;
+
+  WebSocketPushStateReceived(this.stateChange);
+
+  @override
+  List<Object> get props => [stateChange];
+}
+
+class WebSocketConnectionFailed extends FeatureFailure {
+
+  WebSocketConnectionFailed({super.exception});
+}