Added overriding app.test.tsx for default top navigation template. Th…

…is test file properly passes tests now (#1289)

packages/cli/templates/react/igr-ts/projects/top-nav/files/src/app/app.test.tsx

@@ -0,0 +1,14 @@
+import { expect, test } from 'vitest';
+import { render } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+import App from './app';
+import 'element-internals-polyfill';
+
+test('renders without crashing', () => {
+  const wrapper = render( 
+  <MemoryRouter>
+    <App />
+  </MemoryRouter>);
+
+  expect(wrapper).toBeTruthy();
+});