If a bad behaving application tries to make the window/display beep too
often, throttle the beep requests so that we don't end up filling the
Wayland socket queue.

The throttle is set to 50 beeps per second, which far more beeps than
will ever make any sense from a user experience point of view, but will
avoid terminating due to an excessive amount of requests.

https://bugzilla.gnome.org/show_bug.cgi?id=778188