[Feature Request] Better bandwidth in Pangolin UI

[just5ky]

Feature Request

• Right now, the pangolin UI only shows total bandwidth per newt.
• It would be a lot better if we can the following
  • total bandwidth per site
  • live bandwidth per site and/or per newt
• Other way to go about this would be to have some integration with Grafana/Prometheus, that will let us build our own metrics dashboards

Proposed Solution

• Newt total bandwidth is already shown in the UI, need to add a new column to show live bandwidth
• Integration with Grafana by exposing a Prometheus metrics endpoint