Update Chinese language support (#7878)

* Rename zh_hant to zh_Hant

* Fix front-end language mappings

* Remove "zh" code (is "zh_Hans")

* Remap backend translations

* Update frontend translation files

* Fix locale spec for front-end

* Update pt_BR for frontend translations

* Fix pt_BR for backend

* Rename es-mx to es_MX

src/frontend/.linguirc

@@ -8,7 +8,7 @@
         "el",
         "en",
         "es",
-        "es-mx",
+        "es_MX",
         "et",
         "fa",
         "fi",
@@ -24,7 +24,7 @@
         "no",
         "pl",
         "pt",
-        "pt-br",
+        "pt_BR",
         "ro",
         "ru",
         "sk",
@@ -35,8 +35,8 @@
         "tr",
         "uk",
         "vi",
-        "zh-hans",
-        "zh-hant",
+        "zh_Hans",
+        "zh_Hant",
         "pseudo-LOCALE"],
     "catalogs": [{
         "path": "src/locales/{locale}/messages",

src/frontend/src/contexts/LanguageContext.tsx

@@ -25,7 +25,7 @@ export const getSupportedLanguages = (): Record<string, string> => {
     el: t`Greek`,
     en: t`English`,
     es: t`Spanish`,
-    'es-mx': t`Spanish (Mexican)`,
+    es_MX: t`Spanish (Mexican)`,
     et: t`Estonian`,
     fa: t`Farsi / Persian`,
     fi: t`Finnish`,
@@ -41,7 +41,7 @@ export const getSupportedLanguages = (): Record<string, string> => {
     no: t`Norwegian`,
     pl: t`Polish`,
     pt: t`Portuguese`,
-    'pt-br': t`Portuguese (Brazilian)`,
+    pt_BR: t`Portuguese (Brazilian)`,
     ro: t`Romanian`,
     ru: t`Russian`,
     sk: t`Slovak`,
@@ -51,8 +51,8 @@ export const getSupportedLanguages = (): Record<string, string> => {
     tr: t`Turkish`,
     uk: t`Ukrainian`,
     vi: t`Vietnamese`,
-    'zh-hans': t`Chinese (Simplified)`,
-    'zh-hant': t`Chinese (Traditional)`
+    zh_Hans: t`Chinese (Simplified)`,
+    zh_Hant: t`Chinese (Traditional)`
   };
 };
 
@@ -96,14 +96,17 @@ export function LanguageContext({ children }: { children: JSX.Element }) {
           locales.push('en-us');
         }
 
-        let new_locales = locales.join(', ');
+        // Ensure that the locales are properly formatted
+        let new_locales = locales
+          .map((locale) => locale?.replaceAll('_', '-').toLowerCase())
+          .join(', ');
 
         if (new_locales == api.defaults.headers.common['Accept-Language']) {
           return;
         }
 
         // Update default Accept-Language headers
-        api.defaults.headers.common['Accept-Language'] = locales.join(', ');
+        api.defaults.headers.common['Accept-Language'] = new_locales;
 
         // Reload server state (and refresh status codes)
         fetchGlobalStates();