feat: add lun, node and volume details dashboard

[cgrinds]

Thanks to Jeff Asher for sharing these!

Fabricpool isn't working in any of these yet.

[vgratian]

Awesome, finally some proper dashboards!

I tested on Grafana v8.1.1 (90c87a52f7). A few issues or comments:

NetApp Detail: Node - Ready for Export

• (comment) the Node Uptime, Node Fan Status and Node Power Status are fine when you have 2-3 nodes, but harder to read with more nodes: we might want to convert them into a table in the future.
• Ethernet Port Utilization Percent and FC Port Utilization Percent: unit should be `Percent (0.0-1.0): this is inaccurate in our Network dashboard as well)
• In the Panel NFSv3 Frontend Drilldown:
  ** graphs have node="$Node" in the query, this should be node=~"$Node", otherwise we see only data when one node is selected
  ** avg(node_nfs_latency{datacenter="$Datacenter",cluster="$Cluster",node="$Node",nfsv="v3"}) / 1000 - division is redundant, just change the unit from milliseconds to microseconds

[vgratian]

NetApp Detail: Volume Details

• In the panel Per Volume Statistics: most graphs have bad legends, see my screenshot:
  
  This can be improved by adding labels in under the queries.

[vgratian]

I fixed the issues mentioned above.

One issue that I noticed: in the Volume Detail dashboards, in the Per Volume Snapshot Space Used Percent graph, percentages are higher than 100%. Seems like this is an issue on its own, since metrics themselves are higher than 100%.

[vgratian]

screenshot:

[cgrinds]

Thanks Jeff for contributing these and @vgratian for the updates