GlobeControls: Support orthographic camera

[gkjohnson]

Currently when zooming in and out the orthographic camera does not move meaning it does not work with an ortho camera causing the interaction state to not change. One issue is we need to be able to know how much of the earth is visible and at what point to enable rotation.

Setting the near clip plane also needs to be adjusted.

[gkjohnson]

Related to #537, #531

The simplest approach will probably be to use a "virtual" perspective camera that uses a reasonable default FoV (like ~70 deg) positioned such that it matches the view frame at some distance? The problem is which distance.

edit distance from focus point can be calculated based on world size of orthographic projection.