feat(translator): add locale getter (#3451)

framework/core/js/src/common/Translator.tsx

@@ -18,10 +18,20 @@ export default class Translator {
    */
   protected formatter = new RichMessageFormatter(null, this.formatterTypeHandlers(), mithrilRichHandler);
 
+  /**
+   * Sets the formatter's locale to the provided value.
+   */
   setLocale(locale: string) {
     this.formatter.locale = locale;
   }
 
+  /**
+   * Returns the formatter's current locale.
+   */
+  getLocale() {
+    return this.formatter.locale;
+  }
+
   addTranslations(translations: Translations) {
     Object.assign(this.translations, translations);
   }