tracing: use emojis

Our user timings aren't the most accessible at the moment:

They're formatted as:
```txt
choo.emit('foo') [123123]
```
which doesn't look too great. Instead, I was thinking we could improve our user timings by using emojis, and removing the trailing UUID. Making it closer to:
```txt
🚂 emit('foo')
```

Or even:
```txt
🚂 emit [foo]
```
```txt
🚂 emit(foo)
```

This should hopefully help with user timings, and making it all slightly easier to debug.