Login to add login status judgment

lib/flutter_openim_sdk.dart

@@ -7,6 +7,7 @@ export 'src/enum/group_type.dart';
 export 'src/enum/group_verification.dart';
 export 'src/enum/im_platform.dart';
 export 'src/enum/listener_type.dart';
+export 'src/enum/login_status.dart';
 export 'src/enum/message_status.dart';
 export 'src/enum/message_type.dart';
 export 'src/enum/sdk_error_code.dart';