Ticket 49544 - cli release preperation, group improvements
    
    Bug Description:  Improvements to the cli getting ready for user testing.
      The group handling did not have tests nor the ability to add or remove
      members.
    
    Fix Description:
     This adds support for adding and removing users to groups, as well as
     testing that. To improve the tests, duplicate code from topology was
     removed in the cli side, and placed into topologies.py
    
    https://pagure.io/389-ds-base/issue/49544
    
    Author: wibrown
    
    Review by: mreynolds, spichugi (Thanks!)