dillon1000/react

Record "actual" times for all Fibers within a Profiler tree (alt) (#12910)

* Moved actual time fields from Profiler stateNode to Fiber

* Record actual time for all Fibers within a ProfileMode tree

* Changed how profiler accumulates time

This change gives up on accumulating time across renders of different priority, but in exchange- simplifies how the commit phase (reset) code works, and perhaps also makes the profiling code more compatible with future resuming behavior