LibWeb: Convert some CSS parser *Rule classes to using pointers

Previously these were all passed around by value, but some of them
(StyleComponentValueRule and StyleBlockRule) want to include each
other as fields, so this had to change.

Userland/Libraries/LibWeb/CSS/Parser/StyleFunctionRule.h

@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <AK/RefCounted.h>
 #include <AK/String.h>
 #include <AK/Vector.h>
 
@@ -14,11 +15,11 @@ namespace Web::CSS {
 
 class StyleComponentValueRule;
 
-class StyleFunctionRule {
+class StyleFunctionRule : public RefCounted<StyleFunctionRule> {
     friend class Parser;
 
 public:
-    StyleFunctionRule();
+    StyleFunctionRule(String name);
     ~StyleFunctionRule();
 
     String const& name() const { return m_name; }
@@ -38,5 +39,4 @@ private:
     String m_name;
     Vector<String> m_values;
 };
-
 }