LibWeb: Implement state switch for "[CDATA[" in HTML parser

Author: https://github.com/linusg
Commit: 892f6394b8
Pull-request: https://github.com/SerenityOS/serenity/pull/12559

Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.h

@@ -42,6 +42,8 @@ namespace Web::HTML {
 RefPtr<DOM::Document> parse_html_document(StringView, const AK::URL&, const String& encoding);
 
 class HTMLParser {
+    friend class HTMLTokenizer;
+
 public:
     HTMLParser(DOM::Document&, StringView input, const String& encoding);
     ~HTMLParser();