refactor: move test utils to package (#3206)

tests/affine-local/e2e/subpage.spec.ts

@@ -0,0 +1,12 @@
+import { test } from '@affine-test/kit/playwright';
+import { openHomePage } from '@affine-test/kit/utils/load-page';
+import { waitEditorLoad } from '@affine-test/kit/utils/page-logic';
+import { expect } from '@playwright/test';
+
+test('Create subpage', async ({ page }) => {
+  await openHomePage(page);
+  await waitEditorLoad(page);
+  await page.getByTestId('app-sidebar-arrow-button-collapse').click();
+  const sliderBarArea = page.getByTestId('sliderBar-inner');
+  await expect(sliderBarArea).not.toBeInViewport();
+});