Basic indexes support to indexes
Added http server (on a separate host) that provides data to the Prometheus.
Server by default exposes /metrics
endpoint for metrics fetching.
Default config should be extended with:
metrics:
host: "127.0.0.1"
port: 9000
namespace: "indexes" # warn: must not contains dashes.
Added metrics: last_block_processed (gauge), block_processing_time (histogram) (check http://127.0.0.1:9000/metrics)