[feature] added Levenshtein algoritmh, added service object

added case for Levenshtein algoritmh

 refactored card#check_translation

replaced flash to metod -> case-when

added service object - Result

intermediate example service object

Second intermediate example service object

Third intermediate example service object

Fourth intermediate example service object

fixed bug to TranslationResultServise

added views helper - translation_result_helper.rb

added object var

moved Reviews metod to Index controller

added _form to Card, Deck

fixed Levenshtein algoritmh