Support starting the controller with only a subset of the required daemons. This will enable creating separate k8s deployments
if the plan here is to do one deployment for each daemon type, one thing we're going to need to figure out - if we do that, we don't want to have the multithreading piece I don't think? And we don't want to create 2N DagsterInstances (with 2N DB connections, etc. - so we might need to go through a different path for that case.
Maybe a separate entry point / method on DagsterDaemon for the case when there's exactly one daemon? That shares the instance and doesn't run in a thread?