PersonalTools/ Site Setup assumes Site Administrators have the correct permission for the site setup action

[JeffersonBledsoe]

Describe the bug

As explained in #6346 (comment) and #6346 (comment), the current Site Setup button does a check for the role of a user to see if they are able to access the site setup. This makes the assumption that these roles have the correct permission, but it is possible for the permission required and the roles assigned to it to be change, causing a mismatch between the frontend and backend.

We should likely use the @actions endpoint to see whether the plone_setup key is available to know if the user can access the site setup

[davisagli]

Using the actions endpoint sounds like a good way to do this. We already do that for other things in the toolbar.