Add support for hiding the pointer while typing

### Problem

Sometimes when typing, I would rather not have the pointer block what I'm trying to type. This functionality can currently be achieved with tools like xbanish, or to simply move the cursor away (but that is extra movement that could be considered unnecessary and can be annoying if you're doing it a lot). As far as I know, there is no equivalent tool for hiding the cursor in a Wayland session, meaning that it would be useful if this functionality were to be implemented directly.

### Proposal

Add support for (and an option to enable/disable) hiding display of the cursor while the keyboard is in use, and revealing it when the mouse is moved, clicked, etc.

### Prior Art (Optional)

https://github.com/jcs/xbanish