Listens to hello messages on the provided window and calls the provided callback with the connectionAttemptUuid
If the connection fails and is re-attempted a second connection attempt will be passed to the callback
call the returned unsubscribe function to stop listening
Parameters
windowRef: Window
The window to listen for hello messages on
childWindow: Window
The new window that has just been created that will be sending hello messages
Listens to hello messages on the provided window and calls the provided callback with the connectionAttemptUuid If the connection fails and is re-attempted a second connection attempt will be passed to the callback call the returned unsubscribe function to stop listening