PR: Implement support for "vK20" chromatic adaptation transform.

[KelSolaar]

Summary

This PR implements support for Von Tries (2020) chromatic adaptation transform.

References #891.

Preflight

Code Style and Quality

• Unit tests have been implemented and passed.
• Pyright static checking has been run and passed.
• Pre-commit hooks have been run and passed.
• [N/A] New transformations have been added to the Automatic Colour Conversion Graph.
• New transformations have been exported to the relevant namespaces, e.g. colour, colour.models.

Documentation

• New features are documented along with examples if relevant.
• The documentation is Sphinx and numpydoc compliant.

[coveralls]

coverage: 99.978%. remained the same
when pulling 3d30335 on feature/vk20
into 415b517 on develop.

[tjdcs]

We are heading into NAB so I am totally slammed for time but I will try to review after NAB in 2 weeks.

[tjdcs]

I just asked Mark and Che Shen for any updates on the vk20 work before reviewing this

[KelSolaar]

Merging this one as I think it is correct, quoting Mark:

"It’s really just the weighted sum of three whites to obtain the normalizing white for von Kries"