User deletion cleanup task should use less brittle queries to operate

Rather than use a subquery that uses a hardcoded number of rows that are required to be processed, we should instead run queries that checks that all entries for a given user are set to a non zero value. While it will mean more network traffic and processing, with current loads and traffic this should be negligible in the grand scheme of things.

As a note to an exception, USS entry is missing as it is being deleted by the USS API when the cleanup is completed. This is currently handled, and would not impact this update as we are looking for any 0 values in status.