[!!!][TASK] Add native typing to CommandUtility

Nothing particularly exciting, but does remove another
PHPStan baseline message.

A few bits of unnecessary code have been removed or
cleaned up.

Additionally, a few locations in code were calling
CommandUtility::exec() incorrectly in a way that
has always been incorrect. These are fixed now.

Resolves: #97206
Related: #97210
Releases: main
Change-Id: Ia590af575c432833097859a22f6674c4917e59a1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73988


Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>