Arvados

The current report is no longer updated by the backend job that used to do it, so we need something to replace this. The columns in the current report include:

User    Collections Read Size    Collections Persisted Storage    Measured At
        Total (unweighted)    Shared (weighted)    Total (unweighted)    Shared (weighted)

With the addition expired/trashed collections, we probably want to report stats on that as well to show how much space is available to be reclaimed/garbage collected and perhaps what will be expiring "soon."