The demo now registers our web components lazily with a unique name
so that two different apps using the same underlying web compontens
don't clash.

This also disables auto registering and leaves that to the user.

This duplicates the language switcher on the tugraz.at site.

Compared to the previous implementation we now show the next language
and use the translations for the next language, so that users only knowing
english can understand it.

In case of more languages we just cycle through them, which isn't ideal but
good enough for now.

Also use the same reference for removing the event handler, bind creates a new one.