Loads a string translation object, fast query.
This function must only be used when actually translating strings as it will have the effect of updating the string version. For other purposes the getTranslations() method should be used instead.
array $conditions: (optional) Array with conditions that will be used to filter the strings returned and may include all of the conditions defined by getStrings().
Drupal\locale\TranslationString|null Minimal TranslationString object if found, NULL otherwise.
public function findTranslation(array $conditions);