Translating job items - Quota full - Internal Server Error

Thanks for the finding. The issue is caused by a missing exception handling in the batchRequestTranslation callback.

We need to improve the exception handling in the batchRequestTranslation callback.
The self::doRequest needs to be wrapped into a try/ catch block.

try {
      $result = self::doRequest($job, $query_params);
      // Collect translated texts with use of initial keys.
      foreach ($result['translations'] as $translated) {
        $translation[$keys_sequence[$i]]['#text'] = rawurldecode(Html::decodeEntities($translated['text']));
        $i++;
      }
      if (isset($context['results']) && isset($context['results']['translation']) && $context['results']['translation'] != NULL) {
        $context['results']['translation'] = array_merge($context['results']['translation'], $translation);
      }
      else {
        $context['results']['translation'] = $translation;
      }
      $context['results']['i'] = $i;
    } catch (TMGMTException $e) {
      \Drupal::messenger()->addError($e->getMessage());
    }

To overcome issues of incomplete translations in case of an error, the actual translation job needs to be resetted or deleted (needs to be evaluated) in the batchFinished callback.

See attached patch for 2.2.x.