Async event handling is broken on HTML5

[JujuAdams]

https://github.com/JujuAdams/Coroutines/blob/4e9f4ae392725931682ed14c702edc6855cc595f/scripts/CoroutineEventHook/CoroutineEventHook.gml#L57-L63

Extracting the correct event name based on event_type and event_number doesn't work in HTML5 for reasons I haven't yet looked into.