fix: wrap rl_asset_results in VScrollPanel for scrolling

When many assets are returned, the results area needs scroll.
Wrap the target VBox in a VScrollPanel with fixed height.

wwwroot/view_assets.ui

@@ -46,9 +46,15 @@
             ]
         },
         {
-            "widgettype": "VBox",
+            "widgettype": "VScrollPanel",
-            "id": "rl_asset_results",
+            "options": {"height": "600px"},
-            "options": {"padding": "16px"}
+            "subwidgets": [
+                {
+                    "widgettype": "VBox",
+                    "id": "rl_asset_results",
+                    "options": {"padding": "16px"}
+                }
+            ]
         }
     ]
 }