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

lib/api/marianumcloud/cloud_users/cloud_users_actions.dart

@@ -1,18 +1,13 @@
-import 'dart:async';
 import 'dart:convert';
 import 'dart:developer';
-import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:http/http.dart' as http;
 
 import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
-import '../../errors/auth_exception.dart';
-import '../../errors/network_exception.dart';
-import '../../errors/not_found_exception.dart';
 import '../../errors/parse_exception.dart';
-import '../../errors/server_exception.dart';
+import '../../http_errors.dart';
 import '../nextcloud_ocs.dart';
 
 /// Mix of two Nextcloud surfaces:
@@ -42,30 +37,17 @@ Future<http.Response> _send(
 ) async {
   final headers = NextcloudOcs.headers();
 
-  final http.Response response;
-  try {
-    response = await perform(uri, headers);
-  } on SocketException catch (e) {
-    throw NetworkException(technicalDetails: 'Cloud $uri: ${e.message}');
-  } on TimeoutException catch (e) {
-    throw NetworkException.timeout(technicalDetails: 'Cloud $uri: $e');
-  } on http.ClientException catch (e) {
-    throw NetworkException(technicalDetails: 'Cloud $uri: ${e.message}');
-  }
+  final response = (await sendGuarded(
+    'Cloud $uri',
+    () => perform(uri, headers),
+  ))!;
 
   final status = response.statusCode;
   if (status >= 200 && status < 300) return response;
 
-  final body = response.body.replaceAll(RegExp(r'\s+'), ' ').trim();
-  final preview = body.length > 500 ? '${body.substring(0, 500)}…' : body;
-  final detail = body.isEmpty
-      ? 'Cloud $uri -> HTTP $status'
-      : 'Cloud $uri -> HTTP $status body=$preview';
+  final detail = httpErrorDetail('Cloud $uri', response.body, status);
   log(detail);
-  if (status == 401) throw AuthException.unauthorized(technicalDetails: detail);
-  if (status == 403) throw AuthException.forbidden(technicalDetails: detail);
-  if (status == 404) throw NotFoundException(technicalDetails: detail);
-  throw ServerException(statusCode: status, technicalDetails: detail);
+  throwForStatus(status, detail);
 }
 
 class SetUserAvatar {