Feat: Add Tempo to Grafana stack

[yorickdowne]

To support Lighthouse and Grandine trace collection

"Also, if you could stick to https://github.com/sigp/lighthouse-metrics/blob/master/tempo.yaml (components such as metrics_generator etc.) that would be really great, in this case both Lighthouse and Grandine would not need manual messing with metrics department."

[eth2353]

FYI Vero also has tracing support - https://vero.docs.serenita.io/reference/instrumentation/#tracing