Add button matrix / patchbay

In situations like audio patchbays or signal routing, usually a patchbay gui or a matrix of n by n buttons is used. Usually X represents the outputs and Y the Inputs. The connection can be made by clicking the corresponding box. This should result in a callback onConnect/onDisconnect.

Thanks for sharing this idea!
Probably lv_table could be used with some customization but it’s certainly not an out of the box solution.