Add Prometheus/OpenMetrics support #24
Description
To be able to collect metrics from e.g.
https://neo4j.com/docs/operations-manual/current/monitoring/metrics/expose/#metrics-prometheus
https://pulsar.apache.org/docs/latest/deployment/Monitoring/#ConfiguringPrometheus-sd74k7
... we need to add support Prometheus and/or OpenMetrics as a metric source.