Prometheus metrics are outdated/empty

[droserasprout]

Prometheus metrics in dipdup.prometheus are outdated. Some of them need to be dropped, some synced with dipdup.env._MetricManager.

[bigherc18]

I'll start working on this issue now that the other one is ready enough !

[bigherc18]

I was writing a comment detailing the different metrics and what we should do about them but I lost it due to a computer restart, I'll write it again soon but before that I want to ask a question, what do you guys think of making performance._MetricManager the only metrics manager class and the only way we handle metrics, then prometheus metrics would be generated automatically to export the metrics in performance._MetricManager ?

[droserasprout]

@bigherc18 Yes, it would be great to get rid of hardcoded prometheus metrics in favor of some generator around _MetricManager. A separate implementations for Prometheus and API/reports was useful before the stabilization of latter.