feat(HomeController): Kultur-Cookie zur Hauptseite hinzugefügt.

EnvelopeGenerator.Web/Views/Shared/_Layout.cshtml

@@ -4,6 +4,8 @@
 @{
     var nonce = _accessor.HttpContext?.Items["csp-nonce"] as string;
     var userCulture = ViewData["UserCulture"] as Culture;
+    //TODO: instead of default assignment add a middleware for culture
+    userCulture ??= _cultures.Default;
     var isReadOnly = false;
     if (ViewData["IsReadOnly"] is bool isReadOnly_bool)
         isReadOnly = isReadOnly_bool;