remove duplicate code, turn getTMXResults into a static method

* Create ShowResults::getStringFromEntity($entity, $strings) + unit tests
* Make ShowResults::getStringFromEntity() accept an array of localized strings, not just 2 arrays, so as to be able to return results for more than 2 locales
* update views/results.php to use the changes aboveand use a loop to avoid code repetition
* general cleanup of variables to fix typos and consistently use underscore for naming