Show control - disable individual event

Currently you can turn off an entire event list, but it would be great to do this on a event by event basis.

Example use case:

- Time of day -- system startup -- but perhaps we are dark for a while, so we simply want to disable this event from running

- Timecode -- we need to ignore a specific cue from triggering with timecode, but only for this next run, but want to retain that timecode for future use.