Adaptive UI: Added palette options for Okhsl

[bheston]

Pull Request

Description

OK is the best algorithm we have for perceptual color, but the results are not always the intent we want in design. This PR adds some config options to the Okhsl palette:

• Allow customization of the number of steps in the palette, which is useful to increase or decrease contrast in the base design
• Set the saturation of the light and/or dark end to adjust the curve. Base colors with high saturation maintain that saturation even when the lightness is high, which makes them pop too much for some design intents.

Reviewer Notes

Additive changes to the palette.

Test Plan

Tested in Figma.

Checklist

General

• I have included a change request file using $ npm run change
• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation for this project.