[FOLLOWUP][BUGFIX] Set language uid for inline children by default

Resolves: #48883
Resolves: #76048
Resolves: #73609
Releases: master, 7.6
Change-Id: Id782bd41bfe30d9f9574e4b444d6e361ac76d0c6
Reviewed-on: https://review.typo3.org/52148


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>