Add support for role groups

### Steps to Reproduce

1. Login to admin console
2. Try to assign roles to role groups
3. Try to assign role groups to users

### Expected Behaviour

UI should support the use of role groups since spring security core supports this.

### Actual Behaviour

There are no tabs available to edit the RoleGroups or assign them to users.

Start at the admin console's existing role and user assignment UI, then compare its capabilities with Spring Security Core's role-group support. Done means the console provides tabs or controls to edit role groups, assign roles to them, and assign role groups to users.

Written by the indexing model from the issue text.