style: Allow propagating computed style bits from the selector-matching process

This allows us to propagate flags from the container query styles all the
way to the computed style of the element.

The flag for viewport units in container queries has to be different
because it requires rematching, see comments.

Depends on D159851

Differential Revision: https://phabricator.services.mozilla.com/D159852

components/style/selector_map.rs

@@ -359,6 +359,7 @@ impl SelectorMap<Rule> {
                     rule.container_condition_id,
                     stylist,
                     element,
+                    matching_context,
                 ) {
                     continue;
                 }