Visualise bandwidth utilisation in the SCIONLab network

[AnotherKamila]

I believe we already have influxdb metrics for network traffic on the infrastructure nodes of SCIONLab. There are several Grafana plugins which can be configured to visualise this information:

• Topology Panel: this looks like the least amount of work, if it works with our metrics.
• 3D Globe Plugin: looks like it can do all sorts of cool things, and it's on an actual globe rather than abstract topology, but we would need to convert our metrics into "CZML" (whatever that is), which would be work.