TF-3493 Refactor integration test code for performance and maintainability

Signed-off-by: dab246 <tdvu@linagora.com>

integration_test/base/base_test_scenario.dart

@@ -0,0 +1,18 @@
+
+import '../mixin/requires_login_mixin.dart';
+import '../mixin/scenario_utils_mixin.dart';
+import 'base_scenario.dart';
+
+abstract class BaseTestScenario extends BaseScenario
+    with RequiresLoginMixin, ScenarioUtilsMixin {
+
+  const BaseTestScenario(super.$);
+
+  @override
+  Future<void> execute() async {
+    await executeLoginScenario();
+    await runTestLogic();
+  }
+
+  Future<void> runTestLogic();
+}