Protect controller access

This patch uses a technique which is also used by Layout Builder Perms, so they could end up clashing with each other when used together.
It swaps the LayoutBuilderAccessCheck class.

I've been wondering though whether it wouldn't make more sense to override OverridesSectionStorage (which then might clash with layout builder at, but since I maintain both, I can easily write a workaround for that).

And now with patch

We now have tests. Uploaded failing and pass test patches.
Still needs check for all other routes.

removed the debug drupal_set_message call

New patch with a more elegant solution: adding a new access check so both are chained! Credits to Tim for this one! :)

More route checking, LOCKED_SECTION_BLOCK_MOVE is the last one

With LOCKED_SECTION_BLOCK_MOVE now too ... manually tested to be sure as I don't really call a route right now in the test.

Another check for removal of section

Done