NavigationMenu component: Add isSearchDebouncing prop (#28102)

Complementary PR for #27280

packages/components/src/navigation/README.md

@@ -123,6 +123,13 @@ The unique identifier of the menu. The root menu can omit this, and it will defa
 
 When `hasSearch` is active, this function handles the search input's `onChange` event, making it controlled from the outside. It requires setting the `search` prop as well.
 
+### isSearchDebouncing
+
+-   Type: `boolean`
+-   Required: No
+
+Indicates whether the search is debouncing or not. In case of `true` the "No results found." text is omitted. Used to prevent showing "No results found." text between debounced searches.
+
 ### `parentMenu`
 
 -   Type: `string`

packages/components/src/navigation/menu/index.js

@@ -32,6 +32,7 @@ export default function NavigationMenu( props ) {
 		onSearch: setControlledSearch,
 		parentMenu,
 		search: controlledSearch,
+		isSearchDebouncing,
 		title,
 		titleAction,
 	} = props;
@@ -84,7 +85,7 @@ export default function NavigationMenu( props ) {
 				<NavigableMenu>
 					<ul aria-labelledby={ menuTitleId }>
 						{ children }
-						{ search && (
+						{ search && ! isSearchDebouncing && (
 							<NavigationSearchNoResultsFound search={ search } />
 						) }
 					</ul>