codeintel: Change rank behavior for uploads and indexes

Created by: efritz

We were previously using RANK() to find the relative ordering of the upload and index queues. We should instead use ROW_NUMBER() so that several index or upload records with the same insertion time don't occupy the same number.

Previously we would have something like (#1, #1, #1, #4, #4, #6, #7). Now we should have (#1, #2, #3, #4, #5, #6, #7).