[BUGFIX] Properly apply system maintainer role to backend admins

The security fix TYPO3-CORE-SA-2022-005 introduced a synchronization
of backend user and admin tool sessions - without considering these
two documented aspects:

+ If no system maintainer is set up, then all administrators are
  assigned the system maintainer role.
+ In Development context, all administrators are system maintainers
  as well.

Resolves: #97768
Releases: main, 11.5, 10.4
Change-Id: I81dbfc5d07a41a4fa254e1fb50210c74f5e6f02c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74912


Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>