[CLEANUP] Use proper Clickmenu API

The proper way to call up the CSM is with Clickmenu.show().
Many places in the Core still use the deprecated
showClickmenu() function. This patch replaces them all.

Resolves: #20326
Releases: 6.2
Change-Id: Ia2d72b97ae9bf09026d9923051b2c5aec617db5d
Reviewed-on: https://review.typo3.org/20174
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Alexander Opitz
Tested-by: Alexander Opitz
Reviewed-by: Benjamin Mack
Tested-by: Benjamin Mack