Just change all imports and dependencies.

We still need to force the v3 format internally because i18next-scanner
doesn't support the new format and v4 drops support for Safari<13.

By setting compatibilityJSON things should continue to work as before.

Remove any mention of TU Graz.

Since this is very simple JS code and we can't adjust it with
slots etc. just remove the support text.

No longer needs babel, but requries an alpha version of the typescript plugin
for eslint 8 support

We now enable it by default for everyone. The plan is to load the API
user instead and not the person as a next step. This api should work
even for users that don't have a person associated.

Instead of using the namespace which is hardcoded we use the tag name that was
used to register the element (or the "real" tag name in case of a scoped element).

This way if AppShell is regsitered as "dbp-some-app" it can still be overriden by
specifying "dbp-some-app" in the overrides object.

We use i18n.languages in the app-shell to see which languages are available
but this only contains a list of languages it will search in (means, currently
set language, default one and all fallbacks).

We can just set all languages we know as last fallback, so i18n.languages
always contains all languages.

A bit hacky...

Allow globally overriding slots in the light dom of components and use it to override the auth-info slot in the Nextcloud file picker