Improvement to witness count metric

Increased the liveness of cf_witness_count_failure to 10m.

Health endpoint

• Added health endpoint
• Fixed a little bug in witnessCount/WitnessChainTrackingCount

Inizialite counter values

Counters not initialized result in a null value, this means that the first time we increase them it will result in an increase of 0 (null -> 1 doesn't count as 0 -> 1)
With this release we increment on initialization the relevant counters to 1 to avoid such problem.

New configuration setting

• Added the option to disable single metrics from the exporter
• Added a configuration check on start-up that exits the process in case the configuration is not complete

Added arb asset to price delta metric + bugfixes

• Added new assets to cf_price_delta (Arb-eth, Arb-usdc, USDT)
• Fixed a little bug in cf_chain_tracking_witness_count metric's logic

2.5

Arbitrum release.
With this release we update the exporter to accomodate the addition of Arbitrum and the relative changes we've made to the protocol.

Fix bugs

Switched from toHuman() to toJSON() whenever possible.

General improvements

• Improved witnessing metrics -> print list of failing validators
• removed unnecessary imports
• fixed little bugs: handle case where query result is null instead of erroring

Fix: little bugs

Fixed a bugs where we didn't check that the returned value was not null.

2.3.8: Improve witness metric (#51)

Added new metric to better capture failing extrinsic -> we parse the inner error through the metadata and use that as label such that we can differentiate where the error is coming from instead of having the general error system.extrinsicFailed

Added new metric for failing witnesses such that we can use these two new metrics to print the list of failing validators in our alerting system.

Improved witnessing metric for chaintracking -> in case of a very low number of witnesses we check also the previous epoch and use the sum of the two as the total. This will allow us to avoid alerting on false positive after a rotation.