With this new timestamped messaged, the host can properly compare
and evaluate how much time the request got delayed to an issue on a
busy event loop.

This new handler will allow any application developer to register
a function for analyzing or storing performance metrics related to
latencies due to a message delay sending the response back from the
host to the app.

The old field will be preserved with backwards compatibility
with previous versions that still consume this field.

All the telemetry related code is added to the telemetry module to
avoid cluttering the communication layer with nuances about
telemetry.