Change automatic color generation for Voronoiplot

[DanielVandH]

Description

Fixes #4344 by using a consistent method for generating colors. Using this approach the colors will be consistent between plots even if generators were removed or added. The old approach wasn't optimal since the Set defining each_generator(vorn) isn't ordered consistently across tessellations if the generator set changed.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• Added an entry in CHANGELOG.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.

[DanielVandH]

This PR breaks

Voronoiplot for a centroidal tessellation with an automatic colormap.png
Voronoiplot after adding points.png
Voronoiplot for a tessellation with a custom bounding box.png

because of the new color generation method. I've checked them myself and nothing else is broken, it's just the colors. I don't see a consistent way to define the colors that is consistent with the colors generated by the previous method, so is just regenerating the images sufficient?

[ffreyer]

I think it's fine that the automatically chosen colors change, but it would mean that we consider this breaking and delay it until the next breaking release.

[SimonDanisch]

I'm wondering if we can tag this as a patch version, considering that it's not that close to core Makie and the colors are somewhat arbitrary.
I guess I'd let @DanielVandH decide this.

[DanielVandH]

It would be nice to get it in earlier, but I don't mind waiting for another breaking release if you prefer . I would agree with you though that I don't think it's so breaking.