Add and edit users via UI

[janlepsky]

Adding and managing users is currently only available via CLI. The section to manage members in a punq instance already exists and we need options to add and edit users.

Since punq doesn't have support to integrate SMTP for transactional emails, invite links and double opt-in are not possible yet. Therefore, when adding a user, admins could set or generate a password that is changed by the user after login.