On iOS, the Spatial Room will sometimes start playing one or more cues, even if the performance hasn't started #28

During rehearsal and last night's performance, we noticed that sometimes the iOS app (and presumably Safari as well, though I didn't try) will play one or more cues spontaneously upon loading the Spatial Room tab, even before the performance has started.

I traced this to an AbortError that gets fired when we try to play the audio elements and then immediately pause them—related to the click to play functionality on browsers.

Long term, I think we should parameterize some of this code and just omit it entirely when loaded into a native WebView. But in the interim, I think the fix involves waiting for the MediaElement canplay event before trying to play and then pause the audio elements.