- [GUI] Highlight nodes that are exportable as fbx.

- [GUI] Add option to toggle between selecting all subnodes or matching only (using `Alt` key).

AssetStudio.GUI/Components/GameObjectTreeNode.cs

@@ -10,6 +10,10 @@ namespace AssetStudio.GUI
         {
             this.gameObject = gameObject;
             Text = gameObject.m_Name;
+            if (gameObject.HasModel())
+            {
+                BackColor = System.Drawing.Color.LightBlue;
+            }
         }
     }
 }