Fix class not found crash that happens sometimes
In some cases
civicrm_alterMenu hook is called before
civicrm_entityTypes hook. This means that the API calls to DataProcessorOutput and DataProcessor fail because they cannot find the BAO class.
This happens for example when running
cv flush to clear caches on the command line. It only happens sometimes because it depends on the order that CiviCRM loads things and the state of the caches.