[TASK] Clean up UpgradeWizardsService API

Remove implementation details from public API methods

Releases: master
Resolves: #86166
Change-Id: I3605132946d4fa1e92eccfa91498290dab4762c2
Reviewed-on: https://review.typo3.org/58199


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>