[TASK] Avoid GeneralUtility::getContainer() in ClearCacheToolbarItem

EventDispatcherInterface injection is easy here, therefore lets to
so in order to avoid the discouraged global lookup via GeneralUtility.

Also refactor to inject other dependencies.

Resolves: #95101
Releases: master
Change-Id: I4c6db4bbb5e0f10121b75cef5bd57956c093d2b1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70883


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>