Customizing default tenant name based on new "relevant option"

[stefpi]

It would be very nice if the default tenant name could be customised using an option in a docker yml file, instead of it being hard-coded to realtime-dev.

This would be very useful for kubernetes and docker builds which would like a the tenant name to be custom on startup instead of having to integrate a POST request to do so.

I would appreciate your consideration. Thanks!