TF-234 Implement delete a mailbox

lib/features/mailbox/domain/state/delete_multiple_mailbox_state.dart

@@ -0,0 +1,18 @@
+import 'package:core/core.dart';
+
+class DeleteMultipleMailboxSuccess extends UIState {
+
+  DeleteMultipleMailboxSuccess();
+
+  @override
+  List<Object?> get props => [];
+}
+
+class DeleteMultipleMailboxFailure extends FeatureFailure {
+  final exception;
+
+  DeleteMultipleMailboxFailure(this.exception);
+
+  @override
+  List<Object> get props => [exception];
+}