Add a shortcut key to sample color from the screen

The foreground color selector of krita has the function of picking colors from the screen. But, when the window of other reference image software is above the krita window or when the OCIO Lut is used, this function cannot really get color from the screen. So I want to add a function that can really get the screen color. I have deleted some code in the KisScreenColorSampler to get the color on the screen, and the shortcut key has been added, but there are still some problems. there is no icon for color sampling, and the window above krita cannot be sampled, but it can be in the foreground color picker. What should I do to make it appear when using the shortcut and sample from the window above krita? Thank you.

Special thanks @deiflou, this function has been completed as expected.