[TASK] Cleanup EM list utility

The EM has a lot of code related prior to
the inclusion of package management.

This change does a small cleanup in
ListUtility and calling code to make
better use of the new API.

Resolves: #55562
Releases: 6.2
Change-Id: I7aa5f5204ed3552fec617f2cd9e65dac2009486f
Reviewed-on: https://review.typo3.org/27239
Reviewed-by: Wouter Wolters
Reviewed-by: Stefan Neufeind
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring