[cmd] Remove unnecessary icon sizes

Currently the icon for cmd has 16, 24, 32, 48, 64, 72, 80, 96 and 128 pixel icon sizes. ReactOS only uses 16, 24, 32 and 48. With these uneded sizes, the icon file alone is 253KB and the executable is 1,348KB. Without those sizes, the new icon size is 39.6KB and the executable is then 1,133KB. I also added a much crisper 16pixel icon to replace the current blurry 16 pixel size.