Use xcb-xinput for pixel level scrolling under x11
This PR enables pixel level horizontal and vertical scrolling under X11 using the The X Input Extension 2.x. I've tested it with only a mouse, only a trackpad, and both together. It should also work with touchscreen, but I don't have the hardware to test it. Trackpad testing was done under xwayland, mouse testing under xorg.
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Closing in preference of switch to x11rb in #9113 . I'll re-implement it if that is merged.