title: Twig don't render HTML tags in the label form tag
body: <p>When I use this code :</p>
  
  <pre><code>{{ form_widget(form.submit, {'attr': {'class': 'send'}, 'label': '&lt;span id="sendArrow"&gt;&lt;i class="fa fa-arrow-right fa-lg" aria-hidden="true"&gt;&lt;/i&gt;&lt;/span&gt;'}) }}
  </code></pre>
  
  <p><em>Expected output</em></p>
  
  <p><img src="https://i.stack.imgur.com/5YxC3.png" alt="this"></p>
  
  <p><em>Actual output</em></p>
  
  <p><img src="https://i.stack.imgur.com/kLetG.png" alt="output"></p>
  
  <p>I tried to use the raw filter, to clear the cache, to add the label tag in the PHP file... But I have the same result! And when I use the Firefox Developer Tool, I have <a href="https://i.stack.imgur.com/VRsTZ.png" rel="nofollow noreferrer">this</a>: Firefox recognize the node as text...</p>
  
  <p>Thanks!</p>