More performant querying for expired documents

Lucene range queries are a terrible way of finding docs with high cardinality fields. RavenDB doesn't support Lucene filters, but luckily we can use a sorted field which works in a very similar way.
I see, so because the results are sorted, there is no point in processing more because the next ones are always after.
But there is still a bug because we want to `break` out of both the `foreach` and `while(true)`