• writeTextNodeAsHtml: Escape text inside <script> and <style>-like tags in foreign namespaces.
• Fix the tokenizer failing to close CDATA blocks when encountering extra brackets
• Require Dart 3.6
• Limit "Noah's Ark" clause to avoid degenerate O(N^2) when parsing deeply nested formatting elements with unique attributes.
• Added new textContent method to Node class that returns the text content of
  the node.
• Fix XSS vulnerability in htmlToCodeMarkup() by escaping DOCTYPE, element, and attribute names.