Add event type as generic in EventDispatcher

[repalash]

Add event type as generic in EventDispatcher

Add Support for event types in Object3D, Material, MeshBasicMaterial, MeshPhysicalMaterial, MeshStandardMaterial, ShaderMaterial, BufferGeometry, Camera.

Why

Makes it easier to specify types of events like: OrbitControls extends EventDispatcher<Event, 'change'|'end'|'start'>.

Also adds generics for Core classes so that event types can be specified when inheriting the three.js classes.

Checklist

• Checked the target branch (current goes master, next goes dev)
• Added myself to contributors table
• Ready to be merged

One of my first contributions here. Let me know if anything is wrong. Thanks.

[Methuselah96]

I think we want there to be a correlation between the event name and the type of the event, which is something @rafaelsc has started working on as part of #369. I'm not sure if @rafaelsc is still working on that PR, but there are still some unresolved comments on that PR as well.

[repalash]

Hello @Methuselah96, Ah, I didn't see that PR, will go through it.
In this way it's possible to infer the type from the event object type, but I added this as a shorthand for specifying the possible event types without the need for defining a separate typed event interface for each class. (Basically to get autocomplete in addEventListener and dispatchEvent functions for the types like this OrbitControls extends EventDispatcher<Event, 'change'|'end'|'start'>

We can hold on this till #369 is completed and see if it's useful then.

[rafaelsc]

Sorry, @Methuselah96 I finally solved the conflict in my PR. I'm not using GitHub like I used before.

@repalash yes, I started working exactly your current PR, but in the end, I prefer the way that TS does for HTML events. Have autocomplete for the event name and the event properties.

[Methuselah96]

Should be covered by #369, can be reopened if not for some reason.