Monitoring: Add a "Node Exporter Full" dashboard

Copied and adapted from https://grafana.com/grafana/dashboards/1860-node-exporter-full/. This dashboard displays most information that node-exporter provides.

Things like context switches, interrupts, and forks per second that can help find out what's wrong when a service is performing poorly.

added Monitoring label

requested review from @jcalderone

assigned to @florian

approved this merge request

merged

mentioned in commit 0c0fd5cb

mentioned in merge request !335 (merged)