title: padStart() not working in IE11
body: <p>I'm using angularjs 1.7.2 and <a href="https://demos.telerik.com/kendo-ui/scheduler/angular" rel="noreferrer">kendo ui scheduler</a>. All routes are working fine in almost all browser except when it comes to <strong>padStart()</strong> part in IE 11.
  When <strong>padStart</strong> code is taken this error shows up</p>
  
  <p><strong>TypeError: Object doesn't support property or method 'padStart'</strong></p>
  
  <pre><code>let ret = '#' + ((r &lt;&lt; 16) + (g &lt;&lt; 8) + b).toString(16).padStart(6, '0');
  </code></pre>
  
  <p>Is there a way we can handle this or an alternative way for implementing <strong>padStart</strong></p>