fix: always process all events in the queue on x11.

[iwanders]

Commit message:

Previously, there was always a 50ms delay between processing individual events, which could lead to a queue of events building up if the key repeat was higher than 20 Hz. This resulted in the global hotkey release only being detected long after the key is released.

Extra information:

Holding the key for a longer duration led to a larger backlog, and thus a longer delay before the release event was detected. I opted for the while solution instead of reducing the sleep to ensure we always clear out the entire event backlog.

The 50ms delay here does still mean that we incur a worst case delay of 50ms when detecting the keydown and keyup event. I looked for a version of XNextEvent with a timeout and I found this article that describes two approaches to check for events with a timeout, the first requires using poll, the second sets an XSyncAlarm to break out of the blocking XNextEvent call. It add significant complexity, so I don't think the trade off is worth it at this moment.

[amrbashir]

Thanks for your contibutions