TYPO3 Core

As a followup to the API changes
of the clickmenu within #33805 this
change removes any leftovers
of the internals of the clickmenu
using e.g. non-sprite icons, and
removing all non-AJAX-functionality
which was used via alt_clickmenu.php
without &ajax=1 (for the very old topbar
in pre-4.2).

Additionally, it deprecates alt_clickmenu.php,
which was already announced in #33805.

A final followup brings a non-table structure
as well as cleaned up JS calls, and a JSON
Data Exchange.

Relates: #33805
Relates: #18742
Resolves: #62594