Preserve async hook on call to helper

So there is this thing called [async hooks](https://nodejs.org/api/async_hooks.html) in Node now that allow for stuff to be preserved like you would with thread local in other languages. A popular library that uses that is `cls-hooked`. This is very useful to put trace ID and add that trace to the logs when you want to do distributed logging (or add a user ID to have some context for your logs). However, the `machine` that powers sails messes up with this process and we lose the information when an helper is called. I am not sure what happens, but it is most likely related to how the `machine` that powers sails works (by making HTTP calls I believe for each helper). I think @mikermcneil would be the one to answer that since not a lot people seem to have touched this code except him...

Start by tracing the Sails machine's helper invocation path and how the async hook context is propagated or lost. Reproduce the loss of context around a helper call, then verify that the trace or user context remains available after the fix.

Written by the indexing model from the issue text.