[BUGFIX] Migration of CTypes to textmedia misses explicitAllow flags

While the content is migrated, the access rights for restricted users
are not adapted. The migration is adapted accordingly.

Resolves: #71351
Related: #67954
Releases: master
Change-Id: Ib0e1971526a0c1f4322f9a0a901e983f27666f06
Reviewed-on: https://review.typo3.org/44558


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Patrick Schriner <patrick.schriner@diemedialen.de>
Tested-by: Patrick Schriner <patrick.schriner@diemedialen.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>