[BUGFIX] Close file handle only if unused in FileWriter

Keep track of open file handles for resources across instances and
close the handle only on destructing the last known instance using it.

Resolves: #85245
Releases: master
Change-Id: I896f630521136474f843a271b5bd7c752a2efdaf
Reviewed-on: https://review.typo3.org/57204


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>