[BUGFIX] Add silent config upgrader for upgrade wizard settings

Add a migration function to the SilentConfigurationUpgradeService which
takes care of migrating the old class names used for the Install Tool
Upgrade Wizard's information storage to the new (namespaced) class names.

Resolves: #54457
Releases: 6.2
Change-Id: Ib6edb9ec3a8a1dc4873eb38e9a08bc8107db31bb
Reviewed-on: https://review.typo3.org/26451
Reviewed-by: Benjamin Mack
Tested-by: Benjamin Mack
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind