Add option api only

[Funasitien]

I would like to be able to..

Add an option into the config to only host the web api

Is your feature request related to a problem? Please describe.

Having to host the panel when building a custom panel is not efficient

[AuroraLS3]

After considering this alongside #2040 I've decided to close this since it would be difficult to configure API token access control without an UI.

The panel doesn't take any resources if nobody opens it - I assume you have something in place to prevent access to non-api endpoints in the first place.