R1:c020f027bbe6

Add an "Sort by Creation Date" filter to workboards and modularize remaining order behaviors

Summary:
Depends on D20274. Ref T10578. This is en route to an ordering by points, it's just a simpler half-step on the way there.

Allow columns to be sorted by creation date, so the newest tasks rise to the top.

In this ordering you can never reposition cards, since editing a creation date by dragging makes no sense. This will be true of the "points" ordering too (although we could imagine doing something like…