Grafazos: Instance source on all panels

What

modify grafana dashboards generated for easier usage

Why

avoid manually editing the dashboards generated for the L1 vigies.

How

grafazos dashboards all hardware panels are now filtered on instance selected on the drop down variable.

Manually testing the MR

cd grafazos
make
# import ouptput/octez-full.json in your favorite grafana

Also, new added feature, it's possible to filter the storage to show only / and /opt :

cd grafazos
export MOUNTPOINTS="opt"
make
# import ouptput/octez-full.json in your favorite grafana

Checklist

• [-] Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR