adding grafana dashboard for ZFS Local PV that shows the following metrics:
- Volume Capacity (used space percentage)
- ARC Size, Hits, Misses
- L2ARC Size, Hits, Misses
- ZPOOL Read/Write IOs
- ZPOOL Read/Write time
This dashboard was inspired by https://grafana.com/grafana/dashboards/7845
Signed-off-by: Pawan <pawan@mayadata.io>
