adopt MarianumConnectQuery base in remaining queries

lib/api/marianumconnect/queries/get_newsletter_file/get_newsletter_file.dart

@@ -2,9 +2,7 @@ import 'dart:typed_data';
 
 import 'package:dio/dio.dart';
 
-import '../../errors/marianumconnect_error.dart';
-import '../../marianumconnect_api.dart';
-import '../../marianumconnect_endpoint.dart';
+import '../../marianumconnect_query.dart';
 
 /// Downloads the raw PDF bytes of a Marianum Message from
 /// `GET /api/mobile/v1/newsletter/{id}/file`.
@@ -12,23 +10,16 @@ import '../../marianumconnect_endpoint.dart';
 /// Goes through the shared MC dio so the bearer token is attached automatically;
 /// the bytes are handed to `SfPdfViewer.memory` so no auth header has to be
 /// plumbed into the viewer itself.
-class GetNewsletterFile {
+class GetNewsletterFile extends MarianumConnectQuery {
   final String id;
-  final Dio _dio;
 
-  GetNewsletterFile(this.id, {Dio? dio}) : _dio = dio ?? MarianumConnectApi.dio();
+  GetNewsletterFile(this.id, {super.dio});
 
-  Future<Uint8List> run() async {
-    try {
-      final response = await _dio.get<List<int>>(
-        MarianumConnectEndpoint.resolve(
-          'newsletter/${Uri.encodeComponent(id)}/file',
-        ),
-        options: Options(responseType: ResponseType.bytes),
-      );
-      return Uint8List.fromList(response.data!);
-    } on DioException catch (e) {
-      throw mapMarianumConnectError(e);
-    }
-  }
+  Future<Uint8List> run() => guard(() async {
+    final response = await dio.get<List<int>>(
+      endpoint('newsletter/${Uri.encodeComponent(id)}/file'),
+      options: Options(responseType: ResponseType.bytes),
+    );
+    return Uint8List.fromList(response.data!);
+  });
 }