New approach for multiple annotations

- Use the django-sql-utils addon - https://github.com/martsberger/django-sql-utils
- The "distinct=True" flag was not doing what I thought it was doing...

InvenTree/templates/js/part.html

@@ -122,6 +122,9 @@ function loadPartVariantTable(table, partId, options) {
         {
             field: 'in_stock',
             title: '{% trans "Stock" %}',
+            formatter: function(value, row) {
+                return renderLink(value, `/part/${row.pk}/stock/`);
+            }
         }
     ];