Add toggle for BGM, interaction to appliances

Kind of more of an exercise in learning about Node flexibility: I wanted a way to specify playing a BGM at a later point in time, as well as toggling it, and not just autoplay: instead of attaching a script directly on an AudioStreamPlayer, I can attach a more generic script on a Node that just instantiates the ASP on load. Cool~

Also did some refactoring of enums and added interaction to appliances! Now interacting with an appliance will print the available recipes for the appliance. Next step is making it visual and doing cooking.

alexmat2on / gbjam-12

Add toggle for BGM, interaction to appliances #20