Metricsport metrics for conflux
We should add metricsport metrics for conflux, to help with monitoring things like switch frequency, reason for switching (cwnd, alg, orconn block), leg failure rates, set failures rates, leg reattachment, etc.
I think this is likely to be a combination of @dgoulet and me doing this. I can do the ones for the algs, and he can do the ones for the pool. However, I am assigning it to me for now so as I don't lose it.
We don't need it by the first alpha, but should definitely have it by the stable.