IdStory Identity Manager

When the LDAP (e.g. openLDAP) keeps the reference between the Group object and Account object on the Group side, our connID LDAP connector does not support the method for retrieving user's groups.
So we have to be authoritative source of user's groups (Authoritative Merge strategy) for LDAP.

In our older LDAP connector (openICF), we made some changes to support this method, so we were able to use Merge strategy instead of Authoritative Merge.
Other usecase for using the "get" would be, if we had the functionality to show or report difference on account in IdM and account on LDAP.

The goal of this ticket is to copy the code to the newer connID connector. Maybe the good idea would be to check all changes we made to older connector and copy them too.