fix: set correctly the Onlyoffice editor language - EXO-64615 (#207)

The property lang was holding a wrong value of the language like en- or fr- which was not interpreted correctly by the onlyoffice editor and the language was always set to Enlish and Aerbidjan country (defaults)
The fix returns just the language (without the country variant), it adds the country language just for Taiwan chinese and Portugal portuguese as detailed in documentation https://api.onlyoffice.com/editors/config/editor#lang

services/src/main/java/org/exoplatform/onlyoffice/OnlyofficeEditorServiceImpl.java

@@ -2476,7 +2476,12 @@ public static String getUserLanguage(String userId) {
     String lang = Locale.getDefault().getLanguage();
     if(localePolicy != null) {
       Locale locale = localePolicy.determineLocale(localeCtx);
-      lang = locale.getLanguage() + "-" + locale.getCountry();
+      lang = locale.getLanguage();
+      // In case of pt_PT or cn_TW we have to add the country
+      // as detailed in https://api.onlyoffice.com/editors/config/editor#lang
+      if("PT".equalsIgnoreCase(locale.getCountry()) || "TW".equalsIgnoreCase(locale.getCountry())) {
+        lang = locale.getLanguage() + "-" + locale.getCountry();
+      }
     }
     return lang;
   }