https://wpt.fyi/status should also offer to show empty and duplicate runs

[gsnedders]

Debugging #4020 was complicated because the runs weren't showing up anywhere. Had there been a tab on https://wpt.fyi/status to show empty/duplicate runs (or if they just showed up under the invalid tab!), I likely would've been less utterly lost as to what was going on — because I'd have had some admission of what the status of the runs was.