sbws should show relays for diagnostics, even when MIN_REPORT has not been reached

Hi juga,

There's a serious bug in #28563 (moved): sbws is not reporting any relays until MIN_REPORT has been reached.

But we want sbws to always report every relay for diagnostics. If the bandwidth file doesn't have minimum_number_eligible_relays, they should all be marked as "under_min_report=1 vote=0".

https://github.com/torproject/sbws/blob/6070d36022dc2130518dd0c68332166b2bf76c73/sbws/lib/v3bwfile.py#L1352