Improve local favorites performance.

lib/utils/ext.dart

@@ -107,4 +107,15 @@ abstract class MapOrNull{
   static Map<K, V>? from<K, V>(Map<dynamic, dynamic>? i){
     return i == null ? null : Map<K, V>.from(i);
   }
+}
+
+extension FutureExt<T> on Future<T>{
+  /// Wrap the future to make sure it will return at least the duration.
+  Future<T> minTime(Duration duration) async {
+    var res = await Future.wait([
+      this,
+      Future.delayed(duration),
+    ]);
+    return res[0];
+  }
 }