TF-79 Mark as star/unstar in email detailed view

lib/features/email/domain/repository/email_repository.dart

@@ -28,4 +28,6 @@ abstract class EmailRepository {
   );
 
   Future<List<EmailId>> moveToMailbox(AccountId accountId, MoveRequest moveRequest);
+
+  Future<bool> markAsImportant(AccountId accountId, EmailId emailId, ImportantAction importantAction);
 }

lib/features/email/domain/state/mark_as_email_important_state.dart

@@ -0,0 +1,23 @@
+import 'package:core/core.dart';
+import 'package:jmap_dart_client/jmap/mail/email/email.dart';
+import 'package:model/model.dart';
+
+class MarkAsEmailImportantSuccess extends UIState {
+  final EmailId emailId;
+  final ImportantAction importantAction;
+
+  MarkAsEmailImportantSuccess(this.emailId, this.importantAction);
+
+  @override
+  List<Object?> get props => [emailId, importantAction];
+}
+
+class MarkAsEmailImportantFailure extends FeatureFailure {
+  final exception;
+  final ImportantAction importantAction;
+
+  MarkAsEmailImportantFailure(this.exception, this.importantAction);
+
+  @override
+  List<Object> get props => [exception, importantAction];
+}

lib/features/email/domain/usecases/mark_as_email_important_interactor.dart

@@ -0,0 +1,22 @@
+import 'package:core/core.dart';
+import 'package:dartz/dartz.dart';
+import 'package:jmap_dart_client/jmap/account_id.dart';
+import 'package:jmap_dart_client/jmap/mail/email/email.dart';
+import 'package:model/model.dart';
+import 'package:tmail_ui_user/features/email/domain/repository/email_repository.dart';
+import 'package:tmail_ui_user/features/email/domain/state/mark_as_email_important_state.dart';
+
+class MarkAsEmailImportantInteractor {
+  final EmailRepository emailRepository;
+
+  MarkAsEmailImportantInteractor(this.emailRepository);
+
+  Stream<Either<Failure, Success>> execute(AccountId accountId, EmailId emailId, ImportantAction importantAction) async* {
+    try {
+      final result = await emailRepository.markAsImportant(accountId, emailId, importantAction);
+      yield result ? Right(MarkAsEmailImportantSuccess(emailId, importantAction)) : Left(MarkAsEmailImportantFailure(null, importantAction));
+    } catch (e) {
+      yield Left(MarkAsEmailImportantFailure(e, importantAction));
+    }
+  }
+}