TouchPad: Add support for standard G-code thumbnails

[ghost]

The Snapmaker 2.0 is using a proprietary method of encoding thumbnails into G-code. There is a standard method of encoding thumbnails into G-code that all slicers, aside from Luban, use. Adding this support should be trivial, and would make the lives of customers significantly better, as many of us don't use Luban unless there is absolutely no other way of doing something.

Real Ultimaker Cura (not what is in Luban), PrusaSlicer, and SuperSlicer, are magnitudes of order better than Luban, and allow us to work more efficiently. Please allow us to use other slicers as we see fit, as this does not harm Snapmaker in any way.

[bf8392]

+1