Epic filter doesn't work with start date or due date sorting
Summary
When I'm searching for epics and have sorting by start date or due date, the tabs show the correct number of results, but the list actually just displays the empty state. This seems to be due to the sorting method, as it works with sorting by created date and last updated.
Example Project
https://gitlab.com/groups/gitlab-com/-/epics?scope=all&utf8=%E2%9C%93&state=opened&search=fy+21+q3
I added the ~S2 label, as having to find an epic with a specific due date in a list of >100 epics is not only really painful, but even more because I was completely blocked and thought the entire epic search was broken when I first saw this. I had no clue this was due to a certain sorting method not working, and I'm pretty sure users won't play around with sorting if the search incorrectly displays 0 results.
/cc @kokeefe