Variability of admin permissions

**Is your feature request related to a problem? Please describe.**
Right now there is only 1 full admin role but I'd like to also grant some of its permission like user registration, adding routes for Gateway or adding users to specific groups (ideally for group owners).

**Describe the solution you'd like**
The best would be to implement setting specific permissions to groups.

**Describe alternatives you've considered**
Much easier solution is to just create new less powerful admin groups with specific permissions.

**Additional context**
Add any other context or screenshots about the feature request here