* Use pi factor to convert between radiant flux and intensity
* Mark lights as normalized on export
* Add spot light export support
* Add treatAsPoint support for import and export
* Empirically match normalized distant light
* Fix wrong unnormalized point/sphere/disk light unit in Cycles
Overall it should be much closer now for all light types. Point and distant
light units are inconsistent between renderers, so not possible to match
everything there.
Ref #109404
Pull Request: https://projects.blender.org/blender/blender/pulls/109795
05c97df2de