Apply XOR mask to 1 and L mode CUR images

[radarhere]

Resolves #9637

Since PIL, CUR images have had their height halved.

Pillow/src/PIL/CurImagePlugin.py

Lines 65 to 66 in 35d6429

	# patch up the bitmap height
	self._size = self.size[0], self.size[1] // 2

This is because https://en.wikipedia.org/wiki/ICO_(file_format)#File_structure

An ICO or CUR file
...
Images with less than 32 bits of color depth follow a particular format: the image is encoded as a single image consisting of a color mask (the "XOR mask") together with an opacity mask (the "AND mask").

This PR applies the XOR mask to 1 and L mode images.