[BUGFIX] DataHandler: Use the updated field to determine record type

Use the new, updated field values of the current record, to determine
its type value. This allows to pick the correct RTE configuration
for new records with non-default types.

Fixes: #72898
Releases: master, 7.6
Change-Id: If519a9c9357034977ede40d7b709a7d83a3e92c8
Reviewed-on: https://review.typo3.org/46162


Reviewed-by: Sascha Egerer <sascha@sascha-egerer.de>
Reviewed-by: Eugen Lang <laeu1011+gerrit@gmail.com>
Tested-by: Eugen Lang <laeu1011+gerrit@gmail.com>
Tested-by: Jonas Götze <jonnsn@gmail.com>
Reviewed-by: Andreas Wolf <andreas.wolf@typo3.org>
Tested-by: Andreas Wolf <andreas.wolf@typo3.org>