[BUGFIX] RootlineUtility does not consider disablefield

Make sure RootlineUtility::enrichWithRelationFields() respects
the setting of $TCA[$table]['ctrl']['enablecolumns']['disabled'] when
fetching foreign data for the rootline.

Otherwise hidden relations from sys_file_reference are added to the
rootline and cause exceptions in the frontend, instead of being ignored.

Resolves: #56150
Releases: 6.2, 6.1
Change-Id: I21917fec1407a10818058da8ea879b0bb39441a4
Reviewed-on: https://review.typo3.org/28400
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring