RFC 235: Update bundle manager janitor

Created by: efritz

This is part of RFC 235: Move LSIF data to Postgres.

Update the janitor process to understand records in the new code intel database. This will need to be done before writing to the new source and not the old source, which would appear to the janitor as data is missing.

This issue must follow https://github.com/sourcegraph/sourcegraph/issues/13884.