[TASK] Simplify ext:beuser moduleData handling

* Store an array in uc instead of serialized objects
* PHP 7.4 strictness in some classes
* Simplified inheritance chain
* Drop a service class of little use by merging
  calls to controller
* Avoid another ObjectManager->get() call
* Minor bugfix that a shortcut to 'compare users'
  is not reflected in module menu drop down
* Minor cosmetics

Change-Id: I73bd2f884573807a819e4ae0d68c93897641b0f1
Resolves: #94025
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68924


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>