[FEATURE] Filter non-LDAP BE/FE groups in the configuration

The list of required groups should show only LDAP-related groups whereas
the groups to be assigned upon successful authentication should show
only local groups because LDAP-related group membership should be
managed in LDAP and not in TYPO3.

Resolves: #60073
Change-Id: I2775ecd2518822fae5b13a92897f4b4ad81e4ef8
Reviewed-on: https://review.typo3.org/31353
Tested-by: Thierry Brodard
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers