TF-537 Add domain layer for delete a identity

lib/features/manage_account/domain/state/delete_identity_state.dart

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