add parameter to modify host IP and port for Dashboard

[oliverdrechsel]

Thanks for developing Nomadic as a powerful tool.

Currently, the tool is mostly built to run on a powerful server. In case Nomadic is used on a high performance computing environment direct access to the compute nodes is not possible. To this end it is necessary (at least to us) to modify the host IP. By default the Dashboard is launched 127.0.0.1 port 8050.
It would be cool, if this IP address could be modified to make the Dashboard available to users of HPC systems.

It seems that https://github.com/JasonAHendry/nomadic/blob/master/src/nomadic/realtime/dashboard/builders.py needs to potentially be modified, but this modification is beyond my Python abilities.