Metric for running and queued workitems per harware pool

In order to understand the bottlenecks and usage level of the CI hw, a metric to report running and queued workitems is needed. Each hw pool (kvm inten, kvm arm, mac intel, mac arm 11, mac arm 12, mac arm 13, mac arm) needs to be reported separately.

Implementation proposal is that COIN would write the data to influx db periodically (every 5 mins) and then there would a Grafana dashboard to show the data. Another way would be that a bot would fetch data vi OpenNebula APIs and write the results to a db.