Some tablets have a noticable pointer jump on tip down/up, causing unintended
lines during drawing. Likewise, a button event may have an axis update that we
currently ignore. libinput provides tablet axis events only if no other state
changes, the client must instead get the current axis data from the tip/button
event. So let's do this, process the event axis data during tip/button as
well.
A libinput recording to reproduce is the 'dots.yml' in
https://gitlab.freedesktop.org/libinput/libinput/issues/128Fixes#289
176117c5f7