[FEATURE] Introduce ModifyClearCacheActionsEvent

A new PSR-14 based event "ModifyClearCacheActionsEvent"
is introduced in favour of the existing
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['additionalBackendItems']['cacheActions']
hook, which is now marked as deprecated, along with
its interface "ClearCacheActionsHookInterface".

The new event features the same functionality as
the hook. Additionally a new convenience method
`add` is available for the class properties, allowing
extension authors to add their custom actions more
easily. This might be the most common use case for
using this event.

Resolves: #95083
Releases: master
Change-Id: I1e621a00b04cdf43978a6e982b66c397e9437a29
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70870


Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>