Add a dashboard utils file

[cstyan]

During our teams migration to memberlist we missed a few configuration bits because of the split of configuration across files and also across repos. This PR is the first step I want to take to centralize some configuration and observability across loki/mimir/tempo.

This basically takes the dashboard utils file we have in each repo and moves it to a central place, plus adding some functions to the dashboard function so that things like the metric for the template var searches and the dropdown "link to other dashboards" name.

Signed-off-by: Callum Styan [email protected]

[cstyan]

current lint failure is not from my code

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[cstyan]

I'll pick this up again soon

[pracucci]

I'll pick this up again soon

Keep in mind many of these have changed in Mimir since then.