Define ComponentPlugin API type

Just writing down how I think plugins should get registered with the system. Was thinking it'd be nice to do the event thing as a plugin.
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3. Service that relies on Kubernetes and makes calls on Kubernetes, but imposes its own auth / state / storage
```

The distinction between 2 and 3 being that we're trying to solve a better way to make 3 easier for people who are more like 2.