LibWeb: Move PseudoElement enum up a level

This in preparation for changing how we store these, plus it's unwieldy
having to type CSS::Selector::SimpleSelector::PseudoElement.

Userland/Libraries/LibWeb/CSS/Selector.h

@@ -20,6 +20,14 @@ using SelectorList = NonnullRefPtrVector<class Selector>;
 // This is a <complex-selector> in the spec. https://www.w3.org/TR/selectors-4/#complex
 class Selector : public RefCounted<Selector> {
 public:
+    enum class PseudoElement {
+        None,
+        Before,
+        After,
+        FirstLine,
+        FirstLetter,
+    };
+
     struct SimpleSelector {
         enum class Type {
             Invalid,
@@ -75,14 +83,6 @@ public:
             SelectorList not_selector {};
         };
         PseudoClass pseudo_class {};
-
-        enum class PseudoElement {
-            None,
-            Before,
-            After,
-            FirstLine,
-            FirstLetter,
-        };
         PseudoElement pseudo_element { PseudoElement::None };
 
         FlyString value {};
@@ -142,7 +142,7 @@ private:
     mutable Optional<u32> m_specificity;
 };
 
-constexpr StringView pseudo_element_name(Selector::SimpleSelector::PseudoElement);
+constexpr StringView pseudo_element_name(Selector::PseudoElement);
 constexpr StringView pseudo_class_name(Selector::SimpleSelector::PseudoClass::Type);
 
 String serialize_a_group_of_selectors(NonnullRefPtrVector<Selector> const& selectors);