feat: add peerdas metrics dashboard (ethereum#790)

This PeerDAS metrics dashboard is implemented according to the current
PeerDAS metrics specs. It can be used by all the CL clients which
implemented the set of [these
metrics](ethereum/beacon-metrics#13). The
metrics are still under discussion, so, the dashboard is currently in
development.
Filters: by client, job, supernode.

Author: KatyaRyazantseva