Test Transistor Message Handling

[aballman]

Describe the bug
When using a TestTransistor, events are handled by creating a go routine to handle each message on an ad hoc basis. This is entirely different from how events are handled when running in the 'standard' process.

Typically, events are consumed from a queue that X number of works can consume from.
The behavior is entirely different, if 100 events get sent all at once, in testing mode there are 100 go routines running simeltaneously. When running in production, there are X (2?) workers that can process messages concurrently and will take 50 batches to result in the same output.