Replacing getRangeByValue with the most obvious implementation.

On a large asset (1500 shapes, 3 million polys), this improves loading time as follows for the following geometry types:

Cortex: 3.476s to 0.664s
Houdini: 8m 23s to 3m 20s
BoundingBox: 4.272s to 0.763s
PointCloud: 3.256s to 0.426s