[BUGFIX] Make meta data editable for non-writable storages

[BUGFIX] Make meta data editable for non-writable storages

Decouple check for writable files/storage from permission
to edit meta data. Permission to edit meta data is now
only denied when users have only access to the file
via a readonly file mount.

Resolves: #65636
Resolves: #66507
Releases: master, 8.7
Change-Id: I25a0fbc9cf761898dbdb95dec1d3d39bb2f4b7fd
Reviewed-on: https://review.typo3.org/42874
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Joerg Kummer <typo3@enobe.de>
Reviewed-by: Josef Glatz <josef.glatz@typo3.org>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>