The debounce, wheel/wheel-low-res, double-tool and eraser-button plugins can limit
themselves to a specific usage.
The mtdev plugin needs to pass each each event to mtdev and the proximity
timer plugin needs to get each event's timestamp so they cannot be
restricted.
The forced-tool could be restricted but effectively any event on the
devices it works on will have one of those usages set so there's no
point.
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1271>
The vast majority of plugins are only interested in a single or a few
devices. Require that they enable the frame callback for those devices
and don't notify them for any other frames.
Give each plugin a unique index and use that for a bitmask to check if
the plugin wants events for a particular device. If not, skip it.
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1229>
