Role creation command

__Tasks:__

- [ ] test coverage
- [ ] gather feedback for my changes
- [ ] submit changes to the documentation
- [ ] added changelog line
- [ ] make name of role unique
- [ ] show error label in form
- [ ] implement role creation comannd
- [ ] add question for role in user creation command


__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | ??
| Fixed tickets | fixes #466 and fixes #656 
| BC Breaks     | role is now unique (TODO add to changelog and upgrade)
| Doc           | none