feature request: ability to input service credentials in addition to wifi credentials

[dognotdog]

I have a device that needs to be provisioned with the Wifi credentials, but also with credentials to the service it is supposed to connect to. What I'd need are

• UI elements to input service credentials.
• performing service login at the same time as verifying Wifi, to be able to complete device provisioning in a single step.

This seems like it require templates and hooks for the UI, and hooks to be called during the provisioning check.