Admin filter by inventory status and flag

[nathankota]

Miro

As an admin, I would like to be able to filter the list of Sites+Inventories by inventory statuses, and if they have been flagged with an issue (#162). I click on the filter buttons to activate/deactivate one or more filters, and the Site list will change, based on the matching inventory statuses for the Sites. I think it is okay to display all inventories within a site, even if only one inventory matches the selected status, but could be convinced otherwise.