TESTS: Add an integration test for renaming incomplete groups during initgroups
As we implemented the group renaming heuristics to rename only if we can
use another "hint" like the original DN or the SID to know the group is
the same, this patch adds two tests (positive and negative) to make sure
a group with a totally different RDN and hence different originalDN
cannot be renamed but a group whose name changed but the RDN stays the
same can be renamed.
Reviewed-by: Fabiano Fidêncio <firstname.lastname@example.org>