Request: strongly typed event types

[dsgallups]

Hello!

Love the crate :)

I was wondering if you would be willing to update NodeEventType to allow a generate event like so

pub enum NodeEventType<E = OwnedGc<Box<dyn Any + Send + Sync>>> {
   Param { .. },
   Custom(E)
   CustomBytes([u8; 16])
}

This is because I have been working extensively with my own crate, midix to do a lot of midi message processing. I see that you offer an alternative with the midi_events feature. However, unfortunately, their events don't fit my usecase.

It's mostly fine since I can just downcaset from the Custom message, though this is just a little bit of overhead that brings. Would there be any interest in supporting strongly types event types?