Add users/trusted users / packages metrics to prometheus

Basically everything which is currently scraped and shown here https://dashboards.archlinux.org/d/gmvZGXjGk/aur-statistics?orgId=1&from=now-6h&to=now and source code https://gitlab.archlinux.org/archlinux/infrastructure/-/blob/master/roles/prometheus_exporters/files/aur-textcollector.sh