TF-148 Add data layer for cleanup email cache

lib/features/cleanup/data/datasource/cleanup_datasource.dart

@@ -0,0 +1,10 @@
+
+import 'package:tmail_ui_user/features/cleanup/domain/model/cleanup_rule.dart';
+
+abstract class CleanupDataSource {
+  Future<bool> cleanEmailCache(CleanupRule cleanupRule);
+
+  Future<void> saveTimeCleanEmail(DateTime lastTime);
+
+  Future<DateTime?> getTimeCleanEmail();
+}