[TASK] Streamline SameSite cookie handling

Patch for issue #90351 in master branch was merged fast.
Some aspects were missing which are streamlined with this change.

- workspace preview "ADMCMD_prev" using backend user setting
  ("strict" by default)

Resolves: #90380
Releases: master
Change-Id: I8d244db64a438d7537310787934a49abe3ebf28d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63256


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>