Interpolate missing lights in 3D

[mrozycki]

If a light is known to be missing (e.g. it was not correctly detected by the capturer, or it was discarded after detection based on other metrics), its position could be estimated by interpolating its location from the position of neighboring lights.

In the scope of this task, implement an interpolation strategy for points in 3d. At a minimum, a run of missing lights should end up evenly spaced between the nearest two known lights. Ideally, you should also interpolate the derivative of light positions and take that into account.