languages: add guarani (#2603)

* spanish: some necessary, minor rewording for new background sync strings

* en: fix unmetered network typo

* languages: add guarani

Adds strings_gn.arb file.

* fix: remove `,` from beginning and end of file

* tl_constant: add `gn` value

* flags: add guarani (PY) flag

Adds _gn.png_ file.

* languages: add guarani

* localeCountryCode: fix guarani value to 3 letters (grn); making it cohesive with all others

* res/values: replace strings_gn.arb file for appropriate one

* guarani: remove unnecessary `,` at the beginning and end of file

* guarani: fix a lot of syntax errors...

* guarani: remove all remaining trails of Spanish translation; fix all wrongly translated `${}` values back to English

* fix: gn translation

* ci: add ci check for translations

* Update .github/workflows/are_translations_sane.yml

* res/values: adds fixed `strings_gn.arb` file

* res/values: undoes wrong GN=>ES translations on file

* res/values: fix missing `}` for `strings_gn.arb`

* res/values: adds revised `strings_gn.arb` file

* res/values: adds revised `strings_gn.arb` file

* res/values: adds revised `strings_gn.arb` file

---------

Co-authored-by: Czarek Nakamoto <cyjan@mrcyjanek.net>
Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

lib/entities/language_service.dart

@@ -8,6 +8,7 @@ class LanguageService {
     'de': 'Deutsch (German)',
     'es': 'Español (Spanish)',
     'fr': 'Français (French)',
+    'gn': 'Guarani (Guarani)',
     'hi': 'हिंदी (Hindi)',
     'ja': '日本 (Japanese)',
     'ko': '한국어 (Korean)',
@@ -39,6 +40,7 @@ class LanguageService {
     'de': 'deu',
     'es': 'esp',
     'fr': 'fra',
+    'gn': 'grn',
     'hi': 'ind',
     'ja': 'jpn',
     'ko': 'kor',