Allow a dashboard to be archived

[agilliland]

There are times when a dashboard is no longer actively used, but deleting it would be a bit aggressive. It would be nice if as a user you could archive it so that it doesn't show up in the listing, but if needed it was still available to restore.

[salsakran]

@kdoh my understanding is that this is part of the dashboard org project.

[kdoh]

Yup, the plan is to keep features like labels and archiving mentioned in #2204 consistent between questions and dashboards.

[mazameli]

Resolved by #4868