In pointer.c, some axis event was emitted even if the event pointer did not have
current axis.
In X11 backend pointer scroll events seem to be composed of both BUTTON_PRESS
and BUTTON_RELEASE. Therefore we should skip one of them (RELEASE) to avoid
event duplication.
- 'libinput' (backend's) to libinput_context
- 'device' (libinput_device) to libinput_dev
- 'dev' (wlr_device) to wlr_dev
- 'devices' lists tangling of libinput devices to wlr_devices
- 'devices' list of wlr_devices in backend state to wlr_device_lists