Fix "running" fields in bridge summary and bridge details documents

We say that a bridge is "running" if it's contained in the bridge network status, but it also needs the "Running" flag.

This worked fine for relays, because only running relays are contained in the consensus, but bridge network statuses may contain non-running bridges.

We should require the "Running" flag for both relays and bridges, just in case we fall back to a consensus method that contains non-running relays.