[!!!][TASK] Remove deprecated AbstractController

The class AbstractController is removed in favor of
ActionController within Extbase, where all extension
controllers should inherit from.

Releases: master
Resolves: #91527
Related: #91473
Change-Id: Ia32630d04b545b24a18a4a999b1a28c6f2661504
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64377


Tested-by: Benni Mack <benni@typo3.org>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>