title: Add value to existing WP Block Editor setting
body: <p>I would like to add a 33% to the Wordpress Block &quot;Button&quot;. So far it has 25%,50%,75% and 100%. Is it possible to insert my new value into the existing width selector?</p>
  <p>I'm guessing <strong>Block Filters</strong> are the way to go.</p>
  <p>I think I also found the way to get the settings object which might then help me to find out what I need to overwrite. However simply adding this code to my admin.js does not produce any output. <strong>Where would I need to load this?</strong></p>
  <pre><code>const filterBlocks = (settings) =&gt; {
      if (settings.name !== 'core/buttons') {
          return settings
      }
      console.log(settings);
      return settings;
  }
  </code></pre>