Restore bot status functionality during and after listener party

This was removed due to time constraints in the major state refactoring, but should be brought back:

```javascript
streamManager.on('finish', () => {
  this.client.user.setActivity('the stars...', { type: 'WATCHING'});
});

this.client.user.setActivity(`in #${message.channel.name}`);
await streamManager.start().catch((error) => {
  streamManager.stop();
  throw error;
});
```
