[TASK] Remove redundant Fluid overrides

Since Fluid 2.3.0 is now the minimum required version,
we can drop several of the classes/methods TYPO3
uses to change/extend Fluid's behavior. The features
provided by the classes are now provided by Fluid.

Change-Id: I781ef4e6aeedc7aabb4cd3bac0ec8a7416de1ab9
Resolves: #79972
Releases: master
Reviewed-on: https://review.typo3.org/51803


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christer V <cvi@systime.dk>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>