Faster assign lights to clusters (#4345)

# Objective

- Fixes #4234
- Fixes #4473 
- Built on top of #3989
- Improve performance of `assign_lights_to_clusters`

## Solution

- Remove the OBB-based cluster light assignment algorithm and calculation of view space AABBs
- Implement the 'iterative sphere refinement' algorithm used in Just Cause 3 by Emil Persson as documented in the Siggraph 2015 Practical Clustered Shading talk by Persson, on pages 42-44 http://newq.net/dl/pub/s2015_practical.pdf
- Adapt to also support orthographic projections
- Add `many_lights -- orthographic` for testing many lights using an orthographic projection

## Results

- `assign_lights_to_clusters` in `many_lights` before this PR on an M1 Max over 1500 frames had a median execution time of 1.71ms. With this PR it is 1.51ms, a reduction of 0.2ms or 11.7% for this system.

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## Changelog

- Changed: Improved cluster light assignment performance

Co-authored-by: robtfm <[email protected]>
Co-authored-by: Carter Anderson <[email protected]>

Author: 3 people