MM-63669 E2E/Playwright: Move "e2e-tests/playwright/test" to "e2e-tests/playwright" folder (#30647)

* move "e2e-tests/playwright/test" to  "e2e-tests/playwright/test" and expose "ensurePluginsLoaded"

* add test setup, and expose ensurePluginsLoaded and ensureServerDeployment to pw

e2e-tests/playwright/specs/test_setup.ts

@@ -0,0 +1,14 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {test as setup} from '@mattermost/playwright-lib';
+
+setup('ensure plugins are loaded', async ({pw}) => {
+    // Ensure all products as plugin are installed and active.
+    await pw.ensurePluginsLoaded();
+});
+
+setup('ensure server deployment', async ({pw}) => {
+    // Ensure server is on expected deployment type.
+    await pw.ensureServerDeployment();
+});