[BUGFIX] Clear page cache: show status, prevent multiple clicks

Replace the clear cache button with a spinner during the AJAX request.
While the request is executed, the button is no clickable due to
addiional properties and classes being set.

Resolves: #88781
Releases: master
Change-Id: I06d53010d8bd5435ac6fc91ea17ecc6378043f14
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61307


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>