[Feature Request] Flags to enable/disable and set draw distance shader

Currently in 3D mode, it is possible to define a set of points in the space such that performing a specific rotation of that space hides the entire dataset behind what appear to be a draw distance shader positioned at the origin.

While there may be good performance reasons to enable a draw distance shader by default, it would be nice if we had:

• A disable: boolean flag that turns that shader off
• [Optional] If possible, a drawDistance: number = 0 property that sets the distance from the origin along the view-plane normal (VPN) at which the draw distance shader takes effect. drawDistance === 0 (default) should start the effect at the origin, drawDistance > 0 should move the shader away from the origin and camera along VPN, and drawDistance < 0 should move the shader to a point between the origin and camera along VPN.

Thanks for the proposal, will look into this!

https://github.com/PAIR-code/scatter-gl/pull/91