feat: sync cloudId and eTag on sync

mobile/lib/domain/models/asset/asset_metadata.model.dart

@@ -0,0 +1,44 @@
+enum RemoteAssetMetadataKey {
+  mobileApp("mobile-app");
+
+  final String key;
+
+  const RemoteAssetMetadataKey(this.key);
+}
+
+abstract class RemoteAssetMetadataValue {
+  const RemoteAssetMetadataValue();
+
+  Map<String, dynamic> toJson();
+}
+
+class RemoteAssetMetadataItem {
+  final RemoteAssetMetadataKey key;
+  final RemoteAssetMetadataValue value;
+
+  const RemoteAssetMetadataItem({required this.key, required this.value});
+
+  Map<String, Object?> toJson() {
+    return {'key': key.key, 'value': value};
+  }
+}
+
+class RemoteAssetMobileAppMetadata extends RemoteAssetMetadataValue {
+  final String? cloudId;
+  final String? eTag;
+
+  const RemoteAssetMobileAppMetadata({this.cloudId, this.eTag});
+
+  @override
+  Map<String, dynamic> toJson() {
+    final map = <String, Object?>{};
+    if (cloudId != null) {
+      map["iCloudId"] = cloudId;
+    }
+    if (eTag != null) {
+      map["eTag"] = eTag;
+    }
+
+    return map;
+  }
+}