Style variation cards don't match core site editor cards

[ryelle]

The style variation cards don't use the same method for getting the highlighted colors as core does, so the variation cards look different:

Theme	Site	Core
Twenty Twenty-Two
Twenty Twenty-Five

Core attempts to use the text color and button background color (or link color) first, before filtering through the color palette.

We're a little more limited on wp-themes.com because it's not inside a react/Gutenberg context, so we can't easily use useGlobalStyle to fetch these, but maybe something in useStylesPreviewColors can help anyway.