Create a dashboard from the CNO

cf https://docs.google.com/document/d/1ByNIJiOzd6w5csFYpC27NdOydnBg8Tx45uL4-7v-aCM/edit#heading=h.as5l4d8fepgw

Current metrics documentation:

• https://docs.google.com/document/d/1lItYV0tTt5-ivX77izb1KuzN9S8-7YgO9ndlhATaVUg/edit
• https://github.com/ovn-org/ovn-kubernetes/blob/master/docs/metrics.md

Include metrics for:

• pod/svc/netpol setup latency
• ovs/ovn CPU and memory
• network stats: rx/tx bytes, drops, errs per interface (not all interfaces are monitored by default, but they're going to be more configurable via another task: NETOBSERV-1021)