Using dfp with Klaro consent manager

aleix → closed merge request !27

!27 MR was using bad branch dest...
!28 is the good one , with these changes, minor preprocess needs to be done to make it work with klaro. something like:

/**
 * Implements hook_preprocess_HOOK() for dfp templates.
 */
function dfp_klaro_preprocess_dfp_js_head_top(&$variables)
{
  /** @var \Drupal\klaro\Utility\KlaroHelper $helper */
  $helper = \Drupal::service('klaro.helper');

  $service = $helper->matchKlaroApp($variables["google_tag_services_url"]);
  if ($service) {
    $variables['gads_dataset'] = [
      'type' => 'text/javascript',
      'name' => 'dfp_admanager',
      'src'  => $variables["google_tag_services_url"],
    ];
  }
}

/**
 * Implements hook_preprocess_HOOK() for dfp templates.
 */
function dfp_klaro_preprocess_dfp_short_tag(&$variables)
{
  /** @var \Drupal\klaro\Utility\KlaroHelper $helper */
  $helper = \Drupal::service('klaro.helper');
  $service = $helper->matchKlaroApp(TagInterface::GOOGLE_TAG_SERVICES_URL);
  if ($service) {
    $variables['image_attributes'] = $helper->rewriteAttributes($variables['image_attributes'], $service->id());
  }
}

/**
 * Implements hook_preprocess_HOOK() for dfp templates.
 */
function dfp_klaro_preprocess_dfp_tag(&$variables)
{
  _dfp_klaro_preprocess_dfp($variables);
}

/**
 * Implements hook_preprocess_HOOK() for dfp templates.
 */
function dfp_klaro_preprocess_dfp_js_head_bottom(&$variables)
{
  _dfp_klaro_preprocess_dfp($variables);
}

/**
 * Implements hook_preprocess_HOOK() for dfp templates.
 */
function dfp_klaro_preprocess_dfp_slot_definition_js(&$variables)
{
  _dfp_klaro_preprocess_dfp($variables);
}

/**
 * Adds the klaro attributes to each script preprocessed by dfp.
 */
function _dfp_klaro_preprocess_dfp(&$variables)
{
  /** @var \Drupal\klaro\Utility\KlaroHelper $helper */
  $helper = \Drupal::service('klaro.helper');
  $service = $helper->matchKlaroApp(TagInterface::GOOGLE_TAG_SERVICES_URL);
  if ($service) {
    $variables['script_attributes'] = $helper->rewriteAttributes($variables['script_attributes'], $service->id());
  }
}