title: Get attachment url using an attachment ID attribute in backend view of a Gutenberg block
body: <p>If a Gutenberg block has an attachment ID attribute stored, is there are way to dynamically get the url of a specific thumbnail size using that ID?</p>
  
  <p>The attribute will be stored in the block like this:</p>
  
  <pre><code> imageID: {
       type: 'integer',
   },
  </code></pre>
  
  <p>And the idea is to dynamically show that image in the Gutenberg editor view.</p>