Fix PHPUnit test failures on Drupal 11.4 and PHPStan entity storage warnings

Automated tests fail on Drupal 11.4 because core's Standard install profile no longer ships the page and article content types. The Domain Path functional and FunctionalJavascript tests relied on those content types being present, so they now error or fail. This was surfaced by the merge request pipeline in #3611433.

This issue fixes the test suite for Drupal 11.4 (while keeping Drupal 11.3 support) and clears two related PHPStan warnings.

Symptoms on Drupal 11.4

• LogicException: Missing bundle entity, entity type node_type, entity id page (content translation setup).
• Invalid permission "create page content" when creating test users.
• HTTP 500 when creating and viewing nodes of the missing page type.
• HTTP 404 on node/add/page and node/add/article.
• Domain Access form field field_domain_access not found.

PHPStan

The functional and kernel test base classes cached the path alias entity storage in a property, triggering the drupal.entityStoragePropertyAssignment rule twice.

Fix

• Create a dedicated test_page content type in the functional test base instead of relying on the install profile, and re-confirm the Domain Access fields on it so they render on the node form.
• Switch all test references from the profile-provided page and article types to test_page, adding a second pattern-less test_article type where a test needs two bundles.
• Replace the cached path alias storage property with a pathAliasStorage() accessor.

All changes are confined to the test suite. No test methods or assertions were removed (93 test methods and 263 assertions before and after). Verified on Drupal 11.4.1: the full Kernel suite and the main module Functional suite pass.