Update Action View to use HTML5 standards-compliant sanitizers

The modern web is built on HTML5The HTML sanitizers used in Rails 7.0 and earlier, rails/rails-html-sanitizer, use Loofah and Nokogiri, and specifically rely on Nokogiri's HTML4 parser, libxml2.libxml2's HTML4 parser has not kept up-to-date with the HTML5 standards upon which most modern web applications rely, and so it does not behave the same way as modern browsers. Some more context about this statement can be found at RFC: Explore alternatives to libxml2 for HTML parsing · Issue .