Fix creating prefabs directly from prefab objects

#1432

Source/Editor/Windows/Assets/PrefabWindow.Hierarchy.cs

@@ -233,7 +233,7 @@ namespace FlaxEditor.Windows.Assets
 
             contextMenu.AddSeparator();
 
-            b = contextMenu.AddButton("Create Prefab", () => Editor.Prefabs.CreatePrefab(Selection));
+            b = contextMenu.AddButton("Create Prefab", () => Editor.Prefabs.CreatePrefab(Selection, this));
             b.Enabled = isSingleActorSelected &&
                         (Selection[0] as ActorNode).CanCreatePrefab &&
                         Editor.Windows.ContentWin.CurrentViewFolder.CanHaveAssets;

Source/Editor/Windows/Assets/PrefabWindow.cs

@@ -53,6 +53,11 @@ namespace FlaxEditor.Windows.Assets
         /// </summary>
         public PrefabWindowViewport Viewport => _viewport;
 
+        /// <summary>
+        /// Gets the prefab objects properties editor.
+        /// </summary>
+        public CustomEditorPresenter Presenter => _propertiesEditor;
+
         /// <summary>
         /// Gets the undo system used by this window for changes tracking.
         /// </summary>