Add special keyboard combos for Thinkpad P1 Gen 3 (#24862)

Add special keyboard combos for Thinkpad P1 Gen 3 (#24862)

* Add special keyboard combos for Thinkpad P1 Gen 3

These are based on the key codes I've found with evtest. See issue
https://github.com/systemd/systemd/issues/24814 for more details.

I'm not entirely sure what some of these keys are supposed to do,
notably Fn+RShift; this doesn't seem to do anything in Windows on
my machine. Binding them to prog# makes them available to desktop
managers' key bindings at least, in case someone wishes to make
use of this extra keybind possibility.