Gracefully shutdown components

[JamesMurkin]

We should improve our components so they can be gracefully shutdown and terminate open connections before doing so.

Example:
Run server component
Run armadactl to watch some job-set against the server component

When you try to stop the server component, it'll hang and not shut down quickly, due to the open connection.

Things to do:

• Make components gracefully shutdown even when there are open connections
• Make sure it can shutdown faster than the default terminationGracePeriodSeconds, which is currently 5s

Especially for the server, doing this should prevent event loss when the server is forcefully shut down. Potentially it'd be shutdown mid processing of an event.