fix(storage): import MediaType from http package

MediaType is exported from package:http/http.dart, so import it
explicitly with show clause instead of from http_parser package.

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Co-Authored-By: Claude <[email protected]>

Author: grdsdev

packages/storage_client/lib/src/fetch.dart

@@ -3,7 +3,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:http/http.dart' as http;
-import 'package:http/http.dart';
+import 'package:http/http.dart' show Client, MediaType, MultipartFile;
 import 'package:logging/logging.dart';
 import 'package:mime/mime.dart';
 import 'package:retry/retry.dart';