Editable selector port names

For the moment, if we want to make a selector's "modes" clear, we need to add nodes. Which is fine if you already need those for something, but otherwise is a bit of a waste of thermo.

It would be awesome if we could rename the ports by using L1+square on a channel name. As in, tweak the selector, hover over "A," press L1+square to edit it to say something different.

And then when you hover over that input/output, it would show a tooltip with that text. The I/O nub icons could still be A, B, C, etc. But hovering over the nub would show the full name.

I think this could make it much easier for people to understand logic using selectors--which is used for a lot of logic projects.