Expose internal state of astara-rug via an API

There's currently no good way to obtain status of workers, queues, etc. from the outside of the astara-rug orchestrator process.
Spec out a monitoring framework for internal orchestrator status:
    * What was the last thing each worker "did", "status"?
    * What is the queue length for each?
    * What is the state of cluster/peers?

This information is probably very similar to what the `rug-ctl debug` process currently dumps out into the logs.
This info should be available in the REST API and/or a TCP socket.