Sam Atkins 202c55bf28 LibWeb/CSS: Implement the :state(foo) pseudo-class ...

This matches custom elements that have `foo` in their custom states set.

The 2 test failures here are because we don't support `::part()` yet.

2025-07-04 18:10:28 +01:00

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custom-state-set-strong-ref.html

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ElementInternals-states.html

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state-css-selector-nth-of.html

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state-css-selector-shadow-dom.html

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state-css-selector.html

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state-pseudo-class.html

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