feat(robo): new update and update-aborted lifecycle hooks

[Pkmmte]

These will be extremely lightweight (like start and stop) hooks that are called whenever a specific signal is sent to the process. That's it, really.

Use case

Robos hosted on RoboPlay would be notified of new updates to themselves. This would enable:

• Developer: statuses to be marked as "Updating..." by end-user
• Discord.js Plugin: Stop accepting new commands and events
• Server Plugin: Continue accepting requests; act as pre-drain

This would create for a seamless update experience. Of course, this would also be callable in self-hosted environments.