SYSDB: Removing of sysdb_try_to_find_expected_dn()
    
    Currently in order to match multiple LDAP search results we
    use two different functions - we have sysdb_try_to_find_expected_dn()
    but also sdap_object_in_domain().
    
    This patch removes sysdb_try_to_find_expected_dn() and add new
    sdap_search_initgr_user_in_batch() based on sdap_object_in_domain().
    This function covers necessary logic.
    
    Resolves:
    https://fedorahosted.org/sssd/ticket/3230
    
    Reviewed-by: Sumit Bose <sbose@redhat.com>
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>