child_process: implement experimental promises api
First pass here. May be more places to refactor and remove duplicated code. Could also potentially be made faster by pushing stuff to the C++ layer.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
First pass here. May be more places to refactor and remove duplicated code. Could also potentially be made faster by pushing stuff to the C++ layer.