Cleanup event handlers

[stayallive]

This resolves issues where nested operations (like nested queue jobs) were not correctly handling the nesting and messing up the trace.

Also cleaned up and bundled some container resolving for the Dispatcher class.

And removed some @internal methods since they seemed much boilerplate for just a proxy.

This just needs a good test with actual async queues, but we can do that with the final 3.x tests.