This is an improvement on how we diff object details so we can diff in real time and unify several algorithms into one
AsyncTreeDifferences is a generic structure that can diff any tree while AsyncDetailViewDiff is a specialization of that for details panels
Docs: https://docs.google.com/document/d/1rwY-FtTxq2BVptLaMdpKNpzb4hOSn8efm-Z-cF0fBhE/edit?usp=sharing
#rb ben.hoffmann, ben.zeigler, dave.jones
#preflight 6437336e0c4277fc0bdc4d8a
[CL 25027228 by jordan hoffmann in ue5-main branch]
