[Feature] Check attribute and combinator selectors in compat util

[antross]

In packages/utils/src/compat/css.ts

/*
 * Can be passed any selector, but currently only validates pseudo-selectors
 * as most other selector types already have broad support and certain other
 * special cases (e.g. newer attribute and combinator selectors) need special
 * handling to map to the MDN data (which hasn't been done yet).
 */

Is there an issue in MDN for this? If so maybe we should link it? Maybe create another issue in our side to know we have to do this and link to the MDN issue?

Originally posted by @molant in #2296