Feature/improve localization (#1147)

* use locale to set language header

* rewrite i18n provider and drop dependency

* rename file

* rename CrudMixin to HttpRepo

* refactor: code-cleanup

* add crowdin source

* remove unused translations

* grab translations from dev branch

* add translation support for foods, units, and labels

* remove rich import

frontend/composables/api/use-app-info.ts

@@ -5,7 +5,8 @@ import { AppInfo } from "~/types/api-types/admin";
 export function useAppInfo(): Ref<AppInfo | null> {
   const appInfo = ref<null | AppInfo>(null);
 
-  const { $axios } = useContext();
+  const { $axios, i18n } = useContext();
+  $axios.setHeader("Accept-Language", i18n.locale);
 
   useAsync(async () => {
     const data = await $axios.get<AppInfo>("/api/app/about");