LibWeb: User getter and setter for Comment type HTMLTokens

Author: https://github.com/MaxWipfli
Commit: e8e9426b4f
Pull-request: https://github.com/SerenityOS/serenity/pull/8784
Reviewed-by: https://github.com/Hendiadyoin1
Reviewed-by: https://github.com/alimpfard

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

@@ -97,6 +97,18 @@ public:
         }
     }
 
+    String const& comment() const
+    {
+        VERIFY(is_comment());
+        return m_comment_or_character.data;
+    }
+
+    void set_comment(String comment)
+    {
+        VERIFY(is_comment());
+        m_comment_or_character.data = move(comment);
+    }
+
     String tag_name() const
     {
         VERIFY(is_start_tag() || is_end_tag());