refactored HTTP error handling and streamlined UI components by centralizing shared logic and removing redundant parameters

lib/api/marianumcloud/webdav/webdav_api.dart

@@ -2,10 +2,9 @@ import 'package:nextcloud/nextcloud.dart';
 
 import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
-import '../../api_request.dart';
 import '../../api_response.dart';
 
-abstract class WebdavApi<T> extends ApiRequest {
+abstract class WebdavApi<T> {
   T genericParams;
 
   WebdavApi(this.genericParams) {