Frontend first draft

frontend/pshared/lib/api/requests/file_upload.dart

@@ -0,0 +1,15 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'file_upload.g.dart';
+
+
+@JsonSerializable(explicitToJson: true)
+class FileUpload {
+
+  final String objRef;
+
+  const FileUpload({ required this.objRef });
+
+  factory FileUpload.fromJson(Map<String, dynamic> json) => _$FileUploadFromJson(json);
+  Map<String, dynamic> toJson() => _$FileUploadToJson(this);
+}