Custom cassette preview audio

### I am planning on implementing this myself

No

### Describe your request

In vanilla, when you collect a cassette, a preview of the B side music plays. This is accomplished by playing the `event:/game/general/cassette_preview` event with the area ID as a parameter, which does not lend itself to customization. Everest should provide a way to accomplish this for custom maps.

### Additional context

Jungle Helper has a custom cassette that allows this, but having it in Everest itself would be nice.