make new localstorage function file

src/vueLib/login/LoginMenu.vue

@@ -54,6 +54,7 @@ import { useUserStore } from './userStore';
 import { useRoute } from 'vue-router';
 import { Dark } from 'quasar';
 import { useLogin } from './useLogin';
+import { setLocalDarkMode, setLocalLanguage } from 'src/localstorage/localStorage';
 
 const userLogin = useLogin();
 const route = useRoute();
@@ -81,7 +82,7 @@ const loginText = computed(() => {
 //switch between dark and light mode and save it in localStorage
 function toggleDarkMode() {
   Dark.toggle();
-  localStorage.setItem('mode', String(Dark.mode));
+  setLocalDarkMode();
 }
 
 // opens login page if no user is logged in otherwise it serves as logout
@@ -99,6 +100,7 @@ const langSelection = ref(lang);
 // Watch for changes and update i18n locale
 watch(langSelected, (newLang) => {
   i18n.global.locale = newLang;
-  localStorage.setItem('lang', newLang);
+
+  setLocalLanguage(newLang);
 });
 </script>