[TASK] Cleanup update wizard in Install Tool

Cleanup the update wizard classes and move all
classes to one folder instead of the two that
are used now.

Change-Id: Id6a000fe75892d1596984954b2b2f8a78eaf0483
Resolves: #50670
Releases: 6.2
Reviewed-on: https://review.typo3.org/22754
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind