[TASK] Simplify the Clear temp file section in Install Tool

Hide the button for cleaning a directory if the directory is
empty.

Resolves: #82561
Releases: master
Change-Id: I06e76f79b1d814aa5a04a68be544a4c102d7392a
Reviewed-on: https://review.typo3.org/54215


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