Feature/rest calls

- Apologies for the large PR, fixing the tests took some refactoring
- To make the demux executors non-blocking, I added some become/unbecome logic 
- Moved the request work to the executors and they will only pass the request up to parent if they are idle. Not sure if this is ideal
- Return response codes from the api endpoints

I actually thinks it makes sense to keep this is a hierarchical structure so that any work is always run by the boss so to speak. I find that easier to reason about, but I'm open to other ideas.