Noop metrics PR?

[karalabe]

This PR #22083 merged in 4 years ago seems to be mostly noop? It adds support dumping the metrics configs from CLI into a toml, but there's no code written to actually consume that. So unsure what the point is now?

Did this work at some point and got bricked afterwards @MariusVanDerWijden @lightclient ? Based on the code in the original PR, I don't see how it could have.