[TASK] Deprecate generic extbase domain classes

Extbase provides a couple of generic domain repositories
and models, especially frontend / backend users and
groups. Those are flawed by design:

The main issue is that domain models have to be specific
for the domain they are used in. By definition, a generic,
opinionated model can't be "correct" since the domain
it is used in, is unique: It might be that a backend user
email has to be set and the domain does not model
anything but email and firstname?

Many usages don't need backend groups attached to a
backend user model at all, or if they need them, then
maybe in a recursive presentation, or a specific order
or something similar. Having a default group resolution
is thus at least misleading, if not wrong, and can be a
performance issue on top.

A generic model can never foresee its usages. The existing
models thus try to 1:1 adapt the database fields, which
is also misleading since a domain model is not and should
not be a direct representation of a database table. It
would only be by chance if the generic models fit a
specific domain.

Similar issues exist with the repositories: The
CategoryRepository for instance assumes it is a good
idea to set respectStoragePid(false), which is most
likely not the right thing for an extension use.
In the end, whatever extbase delivers here, is most
likely wrong and does not fit the problem domain.

The patch keeps the 'experimental' FAL related models
since those can be actually useful for extensions and
their final fate has not been decided, yet. The other
generic models, especially those with lots of properties
are marked as deprecated with the patch.

Change-Id: I06629fddd0258c517f3fa8bdf2e9c4b342be9678
Resolves: #94654
Related: #83296
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70061


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>