Automate creation of a service account from initial/temporary creds

[Fryguy]

In the documentation we specify a number of steps for a user to create a service account in order to then create a more permanent token from that service account. However, in practice, many users don't see that documentation, create a temporary token from the UI, and use that, only for it to expire a short while later with an error.

Instead we should provide a way for when the user gives us user/pass or a temporary token, we then create the service account+permanent token as use that instead.