[TASK] Remove internal Extbase Object Container code

Since the ObjectManagerInterface methods.
- isRegistered()
- getScope()

are internal, they are substituted by PHP's internal code, and avoid
look ups to the custom ObjectContainer code.

Two constants and further methods about Singleton checks
within Extbase's internal ObjectContainer are removed as they
are now unused as well.

Resolves: #91002
Releases: master
Change-Id: I1ed9ae2749aeabb6ab352057e639946289dde96a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64083


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>