Add the ability to use LODs by distance (level of detail)

[Aitolda]

For example, I've created 4 LODS for an object (two objects technically), with LOD0 having the full amount of polygons (full detail), and LOD3 having the least. They way LOD typically works is at a certain threshold (specific distance) from the camera (not to be confused with the avatar) the system would automatically choose to render a lower LOD, and even further beyond a lower LOD until it reaches LOD3.

Notes on implementation can be found here

Why do we want this? Performance, performance, performance!

[Aitolda]

moved issue to "vircadia/vircadia-native-core#1709" per Kalila