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

@@ -45,6 +45,10 @@
                 }
             ]
         },
+        {
+            "widgettype": "VScrollPanel",
+            "options": {"height": "600px"},
+            "subwidgets": [
                 {
                     "widgettype": "VBox",
                     "id": "rl_asset_results",
@@ -52,3 +56,5 @@
                 }
             ]
         }
+    ]
+}