Add more tests and fix capability logging
systemctl: Avoid ellipsizing when piping output
keymap: Fix wrong assignments to F23

These days, F21/F22/F23 mean Touchpad toggle/on/off. Clean up other assignments
to that from ancient times which belong to keys like "Auto Brightness" (which
doesn't have a keycode and is usually hardwired) or some "launch vendor tool"
key.

https://bugs.freedesktop.org/show_bug.cgi?id=62953