feat: direct call download api by cgo dart

ui/flutter/lib/api/native/model/invoke_request.dart

@@ -0,0 +1,19 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'invoke_request.g.dart';
+
+@JsonSerializable()
+class InvokeRequest {
+  String method;
+  List<String> params;
+
+  InvokeRequest({
+    this.method = '',
+    this.params = const [],
+  });
+
+  factory InvokeRequest.fromJson(Map<String, dynamic> json) =>
+      _$InvokeRequestFromJson(json);
+
+  Map<String, dynamic> toJson() => _$InvokeRequestToJson(this);
+}