[BUGFIX] Respect cross-site error content source

In a multi-site setup, it should be possible to refer to a page
from site A as an error page from site B.

Resolves: #90135
Releases: master, 9.5
Change-Id: Ic3e4669e6279f58fe4953f8253d6329f1d137cd3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62955


Tested-by: Susanne Moog <look@susi.dev>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>