This adds support for distance, pressure, tilt and twist.
Not entirely sure if normalized & raw (x,y) should be exposed
in the eo interface. Also not sure what to do with tilt_x/y
(as used by libinput) or touch/tool width "major/minor" vs.
radius x/y.
Add debug logs in the example, including the distance.
I can't test most of these values due to a lack of compatible
hardware, but the most basic features seem to work :)
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