Summary:
This is reimagining of interoperability layer between Yoga and ShadowViews (at least in Yoga -> RN part).
Goals:
* Make it clear and easy.
* Make clear separation between "what layout what", now parent always layout children, noone layout itself.
* Make possible to interleave Yoga layout with custom imperative layout (may be used in SafeAreaView, Text, Modal, InputAccessoryView and so on).
Reviewed By: mmmulani
Differential Revision: D6863654
fbshipit-source-id: 5a6a933874f121d46f744aab99a31ae42ddd4a1b