Add Aragonese language ('an') support and l10n (#6638)

* Update languages.ts

* Update i18n.web.ts

* Update i18n.ts

* Update helpers.ts

* Create messages.po

* Update lingui.config.js

* Update dates.ts

* Add files via upload

* Update src/components/hooks/dates.ts

Co-authored-by: surfdude29 <149612116+surfdude29@users.noreply.github.com>

* Update src/components/hooks/dates.ts

Co-authored-by: surfdude29 <149612116+surfdude29@users.noreply.github.com>

* Update i18n.ts

* Update messages.po

* Update src/locale/i18n.ts

Co-authored-by: surfdude29 <149612116+surfdude29@users.noreply.github.com>

---------

Co-authored-by: surfdude29 <149612116+surfdude29@users.noreply.github.com>

src/locale/helpers.ts

@@ -119,6 +119,8 @@ export function sanitizeAppLanguageSetting(appLanguage: string): AppLanguage {
     switch (fixLegacyLanguageCode(lang)) {
       case 'en':
         return AppLanguage.en
+      case 'an':
+        return AppLanguage.an
       case 'ca':
         return AppLanguage.ca
       case 'de':