What: Add a new permission under Administration > User to allow creating Users who are "Administrator" Type (e.g. "Create Admin Users").
Why: To allow organisations to decide if their Users responsible to create other users should be allowed to create Administrators or not.
This is especially applicable to creating users via APIs, as currently, in order to allow an API user to create an Admin user, the API user would have to have full Administrator rights as well (which is not recommended and potentially risky). Ideally, it should be possible to limit the API user permission to only creating other users.