[TASK] Clean up extension manager code

This change adapts various strict types, and reduces
some injection within EXT:extensionmanager.

The main issue is: There are main circular dependencies
between Utility classes, which should slowly dissolve,
some safe places have been considered now to
be adapted further in subsequenting patches

In addition, all code is now strict-typed,
as all code is internal within EXT:extensionmanager
this is now finally taken care of.

Resolves: #102897
Releases: main
Change-Id: Idb1bd24a9694bb0204acc276de2bcc38c3b6d7a1
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81948


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>