title: Change UIAlertController's title fontsize
body: <p>I'm trying to change the title <code>fontSize</code> in an <code>UIAlertController</code>, but I can't manage how to set my <code>NSMutableAttributedString</code> to the <code>title</code>-property.</p>
  <p>So for I've been creating the <code>NSMutableAttributedString</code> with the following code:</p>
  <pre><code>let title = NSMutableAttributedString(string: user.fullName)
  let range = NSRange(location: 0, length: title.length)
  title.addAttribute(NSAttributedStringKey.font, value: UIFont.TextStyle.largeTitle, range: range)
  </code></pre>
  <p>Now the tricky part for me is how to figure out how to set the new title to the <code>UIAlertController</code>, because it's expecting a <code>String?</code> value.</p>
  <p>I looked around and found out that I should probably create a <code>UILabel</code> within the completion block when presenting the <code>UIAlertController</code>. But how do I override the <code>title</code>-property in the <code>UIAlertController</code> with my own custom <code>UILabel</code>?</p>
  <pre><code>present(myUIAlertController, animated: true) {
      // Creating the UILabel depending on string length
      // Set the NSMutableAttributedString value to the custom UILabel and override title property.
  }
  </code></pre>
  <p>Or maybe there's even an easier way to solve this?</p>
  <br>
  <h3>My goal is to have like the image below:</h3>
  <p><a href="https://i.stack.imgur.com/34HmJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/34HmJ.png" alt="UIAlertViewController with large title" /></a></p>