Update macOS Launcher Icon

The macOS version of the new launcher logos should conform to the conventions in macOS. Unlike other macOS apps, the new creeper icon doesn't feature rounded corners. macOS icons don't usually fill the entire pixel space of the image, instead using that extra buffer zone for some places where the icon may extend out, or use a shadow. Currently, the entire image space is used, resulting in a visibly larger icon compared to other icons in the dock.