PR: Implement support for "Hellwig and Fairchild (2022) Colour Appearance Model".

[KelSolaar]

Summary

This PR implements support for Hellwig and Fairchild (2022) Colour Appearance Model.

References

• https://onlinelibrary.wiley.com/doi/full/10.1002/col.22792

Preflight

Code Style and Quality

• Unit tests have been implemented and passed.
• Mypy static checking has been run and passed.
• Pre-commit hooks have been run and passed.
• 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 increased (+0.001%) to 99.828% when pulling 9ca8486 on feature/hellwig2022 into bbaea60 on develop.