[TASK] Split import of frontend and backend groups

Resolves: #60945
Change-Id: Ibe5f103de269c1e8315837cb72d4cd4f480eeb0f
Reviewed-on: http://review.typo3.org/32127
Reviewed-by: Thierry Brodard <thierry.brodard@techniconcept.ch>
Tested-by: Thierry Brodard <thierry.brodard@techniconcept.ch>
Reviewed-by: Xavier Perseguers <xavier@typo3.org>
Tested-by: Xavier Perseguers <xavier@typo3.org>