[BUGFIX] Extbase ObjectConverter properly handles instantiation

The extbase ObjectConverter - typically used when mapping
request arguments to target domain models - needs more
fine grained handling to drop ObjectManager usages. We
missed some details with #94451.

The patch takes care of this and adds an explanation
together with possible future options to the codebase.

This fixes deprecation log entries triggered by the
belog module.

Resolves: #94807
Related: #94451
Releases: master
Change-Id: Ia1f1c15c1814d53b42d83213778029908332ede0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70445


Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>