move reattaching user data to own function and call it only after fetching metadata for the first time

MediaBrowser.Controller/Entities/BaseItem.cs

@@ -2053,6 +2053,8 @@ namespace MediaBrowser.Controller.Entities
         public virtual async Task UpdateToRepositoryAsync(ItemUpdateType updateReason, CancellationToken cancellationToken)
          => await LibraryManager.UpdateItemAsync(this, GetParent(), updateReason, cancellationToken).ConfigureAwait(false);
 
+        public void ReattachUserData(CancellationToken cancellationToken) => LibraryManager.ReattachUserData(this, cancellationToken);
+
         /// <summary>
         /// Validates that images within the item are still on the filesystem.
         /// </summary>