[!!!][TASK] Remove deprecated module classes from backend

Removed classes:
TYPO3\CMS\Backend\Module\AbstractFunctionModule
TYPO3\CMS\Backend\Module\AbstractModule
TYPO3\CMS\Backend\Module\BaseScriptClass

Resolves: #87210
Releases: master
Change-Id: I56c92246e7b18fd87707e767f743fd4c84f043a1
Reviewed-on: https://review.typo3.org/59208


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>