Signls should be capable of MIDI CCs as well.

We could add that in 2 ways:

1. each node can either send a midi note or a midi cc. It seems like it's the most comprehensible way to integrate that, and it follow the one-message-per-node philosophy. But I can see it could be challenging in some cases to send a note and a cc at the same time. The Zone node would be very useful in that case, but I'm unsure it would cover all use cases.
2. each node can send a number of midi ccs alongside the note. It would be more flexible, but also more complicated from a UI/UX perspective (need to add additional parameters to nodes) and I would make each grid less readable because one node can do multiple things.

I have a preference for the solution 1, but would gladly take feedback on that.