Feature/areg-fts-sorting-fix - fix for - antibodies that do not appear in the unsorted results but appear in the sorted results

[D-GopalKrishna]

Task description:
Problem - there are some antibodies that do not appear in the unsorted results but appear in the sorted results.
Reason - this happens due to - sorting annotation being the same for different antibodies. This leads to improper sorting and leads to inconsistent results for each page.

Solution - add another F("ix") to include as part of sorting. This will help us to keep the sorting different for every filtered_antibodies. We do so by replacing the sorting annotation with the following:

filtered_antibodies.annotate(
        ix_float=Cast("ix", FloatField()),
        sorting=F("ranking") - F("antibodysearch__defining_citation") / 1000 - F("antibodysearch__disc") * 100 +  F("ix_float") / 1000000
    ).order_by('-sorting')