Added a new language: Persian (Farsi) (#2777)

* added strings_fa.arb

* Add Persian (فارسی) language support

* Update language list to include Persian

lib/entities/language_service.dart

@@ -7,6 +7,7 @@ class LanguageService {
     'en': 'English',
     'de': 'Deutsch (German)',
     'es': 'Español (Spanish)',
+    'fa': 'فارسی (Persian)',
     'fr': 'Français (French)',
     'gn': 'Guarani (Guarani)',
     'hi': 'हिंदी (Hindi)',
@@ -41,6 +42,7 @@ class LanguageService {
     'en': 'usa',
     'de': 'deu',
     'es': 'esp',
+    'fa': 'irn',
     'fr': 'fra',
     'gn': 'grn',
     'hi': 'ind',