[BUGFIX] Unset file properties after signals are triggered

Unsetting file properties needs to happen AFTER
the storage deleted the file, because the storage emits a signal,
which passes the file object to the slots,
which may need all file properties of the deleted file.

Resolves: #81926
Related: #80359
Releases: master, 8.7, 7.6
Change-Id: Ie8e25b30dd99d1ed2afb8ca7b1cc83797887de98
Reviewed-on: https://review.typo3.org/53553


Reviewed-by: Matthias Vogel <typo3@kanti.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>