feat(tasks): group extension folder downloads (#1594)

ui/flutter/lib/api/model/create_task_batch.dart

@@ -10,7 +10,10 @@ class CreateTaskBatch {
   List<CreateTaskBatchItem>? reqs;
   Options? opts;
 
-  CreateTaskBatch({this.reqs, this.opts});
+  bool group;
+  String groupName;
+
+  CreateTaskBatch({this.reqs, this.opts, this.group = false, this.groupName = ''});
 
   factory CreateTaskBatch.fromJson(Map<String, dynamic> json) => _$CreateTaskBatchFromJson(json);
 
@@ -19,11 +22,23 @@ class CreateTaskBatch {
 
 @JsonSerializable()
 class CreateTaskBatchItem {
+  String? rid;
   Request? req;
   Options? opts;
 
-  CreateTaskBatchItem({this.req, this.opts});
+  CreateTaskBatchItem({this.rid, this.req, this.opts});
 
   factory CreateTaskBatchItem.fromJson(Map<String, dynamic> json) => _$CreateTaskBatchItemFromJson(json);
   Map<String, dynamic> toJson() => _$CreateTaskBatchItemToJson(this);
 }
+
+@JsonSerializable()
+class CreateTaskBatchResult {
+  final List<String> taskIds;
+  final String? parentId;
+
+  CreateTaskBatchResult({required this.taskIds, this.parentId});
+
+  factory CreateTaskBatchResult.fromJson(Map<String, dynamic> json) => _$CreateTaskBatchResultFromJson(json);
+  Map<String, dynamic> toJson() => _$CreateTaskBatchResultToJson(this);
+}