Rendering Performance Investigation

[jamiesampey]

Investigate the performance of Cesium rendering when a search returns many avalanches. May need to swap out rendering methods as described in #2

[jamiesampey]

After investigation I've concluded that the Cesium entity API is sufficient for 1.0.0. The ground primitive API might render slightly better (less see-through terrain weirdness, etc) but it's very new and probably not fully baked. Also, you cannot to viewer.flyTo(groundPrimitive) whereas you can viewer.flyTo(entity).

The batch entity rendering isn't that bad. 5-6 avalanches in one view render pretty fast. Some of the delay probably depends on the JSON rest response transfer time.