LibWeb: Add the clip-path property and resolve it for SVG elements

Author: https://github.com/MacDue
Commit: 03f957dc79
Pull-request: https://github.com/SerenityOS/serenity/pull/23736
Issue: https://github.com/SerenityOS/serenity/issues/19648
Issue: https://github.com/SerenityOS/serenity/issues/23006
Reviewed-by: https://github.com/nico

Userland/Libraries/LibWeb/Layout/Node.cpp

@@ -193,7 +193,7 @@ bool Node::establishes_stacking_context() const
     // - perspective
     // - clip-path
     // - mask / mask-image / mask-border
-    if (computed_values().mask().has_value())
+    if (computed_values().mask().has_value() || computed_values().clip_path().has_value())
         return true;
 
     return computed_values().opacity() < 1.0f;
@@ -796,6 +796,9 @@ void NodeWithStyle::apply_style(const CSS::StyleProperties& computed_style)
     if (auto mask = computed_style.property(CSS::PropertyID::Mask); mask->is_url())
         computed_values.set_mask(mask->as_url().url());
 
+    if (auto clip_path = computed_style.property(CSS::PropertyID::ClipPath); clip_path->is_url())
+        computed_values.set_clip_path(clip_path->as_url().url());
+
     if (auto fill_rule = computed_style.fill_rule(); fill_rule.has_value())
         computed_values.set_fill_rule(*fill_rule);