[BUGFIX] Improve install tool temporary assets removal

Maintenance > Remove temporary assets now properly lists
statistics for FAL processed files and allows to clear them.

Releases: master
Resolves: #83034
Change-Id: Ic9238c88648d98a76a0cbd4015820d51bffde0fa
Reviewed-on: https://review.typo3.org/57837


Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Tested-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>