title: String.Format not work in TypeScript
body: <p><code>String.Format</code> does not work in <code>TypeScript</code>.<br>
  Error:</p>
  
  <blockquote>
  <pre><code>The property 'format' does not exist on value of type 
   '{ prototype: String; fromCharCode(...codes: number[]): string; 
   (value?: any): string; new(value?: any): String; }'.
  </code></pre>
  </blockquote>
  
  <hr>
  
  <pre><code>attributes["Title"] = String.format(
      Settings.labelKeyValuePhraseCollection["[WAIT DAYS]"],
      originalAttributes.Days
  );
  </code></pre>