feat: improve Thunder's menu GQLS for better accessibility and SEO

[IT-Cru]

To improve accessibility and SEO of menus in Thunder GQLS related projects it would be good to add following elements from Drupal core to Thunder's menu GQLS schema for each menu item.

• [x] Description
• [x] Expanded
• [ ] Attributes (not included in this PR yet!)

Discussion with community

Attributes are not included, because here some general key/value Attribute type should be added to Thunder's GQLS and maybe GraphQL's data producer for menu_link_attribute should be checked, if this could not also provide an array of attributes instead of using it per attribute.

These attributes could be useful for other contrib modules like menu_link_attributes to get its data via GraphQL query.

What is missing

• [ ] Testing data for menus needs to be extended to validate data for new GraphQL fields.
• [ ] Update of Headless API docs needs to be updated in menu section.

Make sure these boxes are checked before submitting your pull request - thank you!

• [ ] All coding styles are fulfilled. (How to check for cs issues?)
• [ ] All tests are running locally. (How to run the test?)
• [ ] Necessary update hooks are provided.
• [ ] User roles have correct access for new introduced permission.
• [ ] Every thunder module has a README.md in its root. Follow this guidelines, but we don't need every topic.
• [ ] Code is covered with well-balanced amount of inline comments.
• [ ] New features or changes are documented.

If you are really awesome, then your feature is covered by additional tests. Well done!