Display config import errors instead of generic message

[jhedstrom]

In the config export command, if there are errors, it currently just throws a generic exception:

      if ($config_importer->getErrors()) {
        throw new \Drupal\Core\Config\ConfigException('Errors occurred during import');
      }

Rather, it would be nice to loop through those and display them as they contain meaningful information about what went wrong.

[jhedstrom]

Latest 9 and 8 versions display this just fine. I'd misread the code. We show them below:

    catch (ConfigException $e) {
      // Return a negative result for UI purposes. We do not differentiate
      // between an actual synchronization error and a failed lock, because
      // concurrent synchronizations are an edge-case happening only when
      // multiple developers or site builders attempt to do it without
      // coordinating.
      $message = 'The import failed due for the following reasons:' . "\n";
      $message .= implode("\n", $config_importer->getErrors());

      watchdog_exception('config_import', $e);
      return drush_set_error('config_import_fail', $message);