render skeleton in the intermediate state

Author: just-boris

src/app-layout/visual-refresh-toolbar/widget-areas/before-main-slot.tsx

@@ -15,7 +15,13 @@ import styles from '../skeleton/styles.css.js';
 
 export const BeforeMainSlotImplementation = ({ toolbarProps, appLayoutState, appLayoutProps }: SkeletonPartProps) => {
   if (!isWidgetReady(appLayoutState)) {
-    return null;
+    return (
+      <BeforeMainSlotSkeleton
+        toolbarProps={toolbarProps}
+        appLayoutProps={appLayoutProps}
+        appLayoutState={appLayoutState}
+      />
+    );
   }
   const { activeDrawer, navigationOpen, navigation, expandedDrawerId, navigationAnimationDisabled } =
     appLayoutState.widgetizedState;