More metrics requests

[martinconic]

Summary

From node operator point-of-view,
/metrics results are not deemed that useful in comparison to JSON api responses. They are mostly counters (having 0 value). A proper beehive dashboard (with x number of beenodes) using grafana and prometheus, needs metrics export for all the values that are listed in the following JSON APIs,
/health
/status
/redistributionstate
/topology
/stake
/wallet
/chequebook/balance

additionally, these metrics would be useful too.

bins-wise chunk read/write count
bins-wise connected peer count
Network read/write count
Concurrent connected sockets count

Motivation

Implementation

Drawbacks