This just fixes the check in set_send_events for whether the mode has
changed. LIBINPUT_CONFIG_SEND_EVENTS_ENABLED is 0 so the bitmask check
cannot be fixed, but Sway doesn't allow multiple modes to be set anyway
(not really sure why you would need to) so a basic equality check works
This adds a libinput_config change type to the input event for when
the libinput config for a device changes
In order for this to be possible to track, the libinput config code
had to be refactored. It is now extracted into a separate file to
isolate it from the rest of the input management code.