title: symfony easyadmin custom form builder
body: <p>I use symfony 3.4 and easycorp/easyadmin-bundle 1.17</p>
  
  <p>Config form easyadmin :</p>
  
  <pre><code>form:
      fields:
          - { type: 'group', label: 'Basic Information', icon: 'envelope-o', css_class: 'col-sm-8' }
          - { property: 'title' }
          - { property: 'status' }
          - { type: 'group', label: 'Legal Information', icon: 'briefcase', css_class: 'col-sm-4' }
          - { property: 'pdfFile', type: 'file' }
  </code></pre>
  
  <p>In AdminController :</p>
  
  <pre><code>/**
   * @param $entity
   * @param $view
   * @return \Symfony\Component\Form\FormBuilder
   */
  protected function createQuotationEntityFormBuilder($entity, $view)
  {
      $formBuilder = parent::createEntityFormBuilder($entity, $view);
  
      $formBuilder-&gt;add('customer', EntityType::class, array(
              'class' =&gt; 'AppBundle:Person',
              'label' =&gt; false,
              'by_reference' =&gt; false,
              'query_builder' =&gt; function(EntityRepository $er) {
                  $user = $this-&gt;get('security.token_storage')-&gt;getToken()-&gt;getUser();
                  $query = $er-&gt;createQueryBuilder('person')
                      -&gt;leftJoin('person.userCreated', 'user')
                      -&gt;andWhere('person.type = :type')
                      -&gt;setParameter('type', 2) // à changer c'est en dur!
                  ;
                  if (in_array("ROLE_ADMIN", $user-&gt;getRoles())) {
                      $query-&gt;andWhere('user.company = :company');
                      $query-&gt;setParameter('company', $user-&gt;getCompany());
                  } else {
                      $query-&gt;andWhere('user.id = :user');
                      $query-&gt;setParameter('user', $user-&gt;getId());
                  }
  
                  return $query;
              },
              'multiple' =&gt; false,
              'expanded' =&gt; false,
              'attr' =&gt; ['data-widget' =&gt; 'select2'],
              'placeholder' =&gt; 'label.form.empty_value'
          )
      );
  
    return $formBuilder;
  }
  </code></pre>
  
  <p>In my form builder I want to add a field "customer" but it appears at the end, the rendering of the form is not good (cf. image), someone would have an idea so that I can insert the field "customer" after the field "status"</p>
  
  <p><img src="https://i.stack.imgur.com/lZndy.png" alt="Example of form"></p>
  
  <p>Thanks in advance</p>