use gomuks for downloading media

lib/models/requests/download_media.dart

@@ -0,0 +1,16 @@
+import "package:freezed_annotation/freezed_annotation.dart";
+part "download_media.freezed.dart";
+part "download_media.g.dart";
+
+@freezed
+abstract class DownloadMediaRequest with _$DownloadMediaRequest {
+  const factory DownloadMediaRequest({
+    required Uri mxc,
+    @Default(false) bool encrypted,
+    @Default(false) bool isAvatar,
+    @Default(false) bool thumbnailAvatar,
+  }) = _DownloadMediaRequest;
+
+  factory DownloadMediaRequest.fromJson(Map<String, Object?> json) =>
+      _$DownloadMediaRequestFromJson(json);
+}