use ocs.data.nextcloud.storage.num_users to get the number of users + set update interval to 3 hours to all ocs.data.nextcloud.storage metrics

Merge branch 'master' of https://git.rcasys.com/git/pmarini/nextcloud-monitoring-dashboard

update names of the dashboards

change name to "Nextcloud by RCA Systems"

start working on discovery for http agent

introduce nc_quota metrics + improvements to dashboard layout

templates use active checks as item type; start tracking the ZFS template