[!!!][TASK] Migrate DB field fe_users.image to FAL

Using the File Abstraction Layer for this field as well,
like it is handled within tt_content.image and pages.media
already.

Also, the patch adds a migration wizard in the install
tool to move existing images to the File Abstraction Layer.

Resolves: #74375
Releases: master
Change-Id: I157d619dec18ef24e7d1e2d8694ed150304549d7
Reviewed-on: https://review.typo3.org/47139


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>