Summary:
We are removing `reactBridgeDidFinishTransaction`.
Why?
* It is a performance drain. Supporting this requires dispatching main-thread block on every single transaction complete;
* It has "too broad" non-conceptual semantic which encouraged using this as a "band-aid solution" for poorly designed components;
* It is conceptually incompatible with new approaches that we are trying to implement to optimize the render layer;
* It was deprecated for very long time.
Reviewed By: mmmulani
Differential Revision: D6549729
fbshipit-source-id: 58094aab982c67cec3d7fa3b616c637cb84d697f
d2dc451407