[BUGFIX] FormEngine databaseRow compatibility with old methods

Introduce a helper method to fake old databaseRow layout at some
places where old methods expect a flat array.

Resolves: #69618
Releases: master
Change-Id: I3657393844f141623187d01744f812cc6fa1adc1
Reviewed-on: http://review.typo3.org/43152


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>