TF-148 Add domain layer for cleanup email cache

lib/features/cleanup/domain/state/cleanup_email_cache_state.dart

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