[FOLLOWUP][FEATURE] Implement configuration for CKEditor

Use correct field to determine page uid

Resolves: #78917
Releases: master
Change-Id: I01101640ff8ac1d801ef1619f8bc3c885aee2713
Reviewed-on: https://review.typo3.org/51555


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>