[BUGFIX] Translation of extbase-core

Made massages from validators and property errors translatable.

Change-Id: I376f55a22d9e7d822146f0f935b1de24098b37cf
Fixes: #6538
Releases: 6.0, 6.1
Reviewed-on: https://review.typo3.org/16544
Reviewed-by: Georg Ringer
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring