Toggle for Touchscreen

### Problem

Sometimes my kids run by and touch my screen while I'm otherwise using the computer. For those of us with touchscreens, it would be nice to disable the touchscreen.

### Proposal

In the same vein as the toggle for rotate lock, it would be nice to have a toggle to enable/disable the touchscreen. It doesn't necessarily need to turn it off, although the power savings would be nice, but just ignoring the input from the touchscreen device would be good. Only display this toggle if a touchscreen is detected. Maybe this is also seen as a tablet to the system, so that would be something to consider.

### Prior Art (Optional)

Rotate lock toggle is how I envision this, both in area it's located and in switch states. On/Off, easy peasy.