SPIKE: Add more specific trigger event types

[gitKrystan]

1. Ensures any provided options are valid to initialize the event type for the provided eventType.
2. If an actual element is provided, ensures the given event type is valid for that element. Only allows CustomEventInit options if not. (This falls apart if you use a string as the target argument though.)
3. When you are typing, all of the possible eventType options are listed in the code completion dropdown. Unfortunately, this kind of falls apart when it gets to the options, as code completion doesn't seem to pick up anything past EventInit there.