[FEATURE REQUEST]Add BTT GCODE thumbnails

[luc-github]

It was raised to me that now BTT TFT support thumbnails in gcode it is even documented https://github.com/bigtreetech/BIGTREETECH-TouchScreenFirmware?tab=readme-ov-file#adding-gcode-thumbnails

I think it would be fun to add this feature also if possible - it would need to add an image decoder which is not an issue in theory I need to see the impact on low memory screens, but at first sight looks possible on others ^_^ TBC