Place cursor at end of extensions search box on autofill (#55254)

* Place cursor at end of extensions search box on autofill

* Use position instead of selection

src/vs/workbench/parts/extensions/electron-browser/extensionsViewlet.ts

@@ -486,6 +486,7 @@ export class ExtensionsViewlet extends ViewContainerViewlet implements IExtensio
 		event.immediate = true;
 
 		this.searchBox.setValue(value);
+		this.searchBox.setPosition(new Position(1, value.length + 1));
 	}
 
 	private triggerSearch(immediate = false): void {