🚸 🐛 Fix HMR issues & change lang without reload

- Fix HMR issues due to circular import of "language" and "i18n"
- Move i18n to seperate file
- Dynamically update language instead of doing a full page reload

src/views/SettingsView.vue

@@ -5,9 +5,9 @@ import {
   classFilter,
   possibleTimetableGroups,
   timetableGroups,
-  language,
   theme,
 } from "../store";
+import { language } from "../i18n";
 
 // eslint-disable-next-line no-undef
 const gitHash = GITVERSION;
@@ -20,7 +20,11 @@ const gitHash = GITVERSION;
     <p>{{ $t("settings.text.filtering") }}</p>
     <select v-model="classFilter">
       <option value="none">{{ $t("timetable.setup.prompt") }}</option>
-      <option v-for="option in classList" :value="option" :key="option">
+      <option
+        v-for="option in classList.length > 0 ? classList : [classFilter]"
+        :value="option"
+        :key="option"
+      >
         {{ option }}
       </option>
       <option value="other">{{ $t("settings.other") }}</option>