Allow CMS Author to delete a page

Note that this will require a delete() method in \Drupal\experience_builder\Controller\ApiContentControllers + a route.

wim leers → credited jessebaker → .

Looking good! A few TODOs that need doing, one genuine bug, and a request for a helper method.

The new e2e test is failing:

    cy:command ✔  findByLabelText	Page options for Empty Page
      cy:command ✔  click	
      cy:command ✔  contains	div.rt-BaseMenuItem, Delete page
      cy:command ✔  click	
      cy:command ✔  contains	button, Delete page
      cy:command ✔  click	
        cy:fetch ➟  GET http://localhost/web/session/token
                    Status: 200
        cy:fetch ➟  DELETE http://localhost/web/xb/api/content-delete/xb_page/2
                    Status: 204
      cy:command ✘  wait	@deletePage
        cy:fetch ➟  GET http://localhost/web/xb/api/content/xb_page
                    Status: 200

Approved the BE pieces of this MR. 👍

Still needed:

1. failing tests, see #10
2. the (trivial) openapi.yml feedback has not yet been addressed

traviscarden → changed the visibility of the branch 3503414-allow-cms-author to hidden.

traviscarden → changed the visibility of the branch 3503414-allow-cms-author to active.

Approved by all codeowners

Thanks, everyone.

Some follow ups from this issue
- 🐛 Deleting a content entity should clear its values from the auto-save store Active
- 🐛 Define what should happen if you delete a page while you are editing it Active

Automatically closed - issue fixed for 2 weeks with no activity.