feat(translate): added getDefaultLang method

Author: ocombe

src/translate.service.ts

@@ -104,6 +104,14 @@ export class TranslateService {
         this.defaultLang = lang;
     }
 
+    /**
+     * Gets the default language used
+     * @returns string
+     */
+    public getDefaultLang(): string {
+        return this.defaultLang;   
+    }
+
     /**
      * Changes the lang currently used
      * @param lang