TF-675 Handle upload attachment use isolate

lib/features/upload/domain/model/upload_task_id.dart

@@ -0,0 +1,13 @@
+
+import 'package:equatable/equatable.dart';
+
+class UploadTaskId extends Equatable {
+  final String id;
+
+  const UploadTaskId(this.id);
+
+  factory UploadTaskId.undefined() => const UploadTaskId('');
+
+  @override
+  List<Object> get props => [id];
+}