feat(server,web): make user deletion delay configurable (#7663)

* feat(server,web): make user deletion delay configurable

* alphabetical order

* add min for user.deleteDelay in SettingInputField

* make config.user.deleteDelay SettingInputField min consistent format

* fix e2e test

* update description on user delete delay

mobile/openapi/test/system_config_dto_test.dart

@@ -91,6 +91,11 @@ void main() {
       // TODO
     });
 
+    // SystemConfigUserDto user
+    test('to test the property `user`', () async {
+      // TODO
+    });
+
 
   });