title: convert string to URL
body: <p>I can't convert this string to URL 
  URL String: "<a href="http://someurl.com/Files/%D9%85%D9%88%D8%A7%D8%AF" rel="nofollow noreferrer">http://someurl.com/Files/مواد</a> غذایی/برنج و ماکارونی/6260100339286.jpg"</p>
  
  <p>I tried with this codes but get an error (can't unwrap) :</p>
  
  <pre><code>let standardString = string.addingPercentEncoding(withAllowedCharacters: .alphanumerics) 
  URL(String: standardString)!
  </code></pre>