Feature request: Use a different window class name (WM_CLASS) for selection

[UtkarshVerma]

Windows 10's snipping tool is really intuitive to use. When the tool is opened, it blurs the entire region and selecting a region unblurs the selected region.

When using a compositor like picom, I can easily specify regions to be blurred based on the WM_CLASS property. I'm not sure but I think this only requires changing this line in the source code:

slop/src/xshaperectangle.cpp

Line 45 in ed94f0c

char name[] = "slop";