Bug 15058: Update German web installer sample files for 3.22

Bug 15058: Update German web installer sample files for 3.22

- Completes translations in German web installer sample files.
- Adds AddressFormat = German to the default system preference
  settings.

To test:
- Run the web installer in German with all sample files selected
- Confirm no error messages are shown
- Bonus: if you speak German, check spelling and translations

Signed-off-by: Zeno Tajoli <z.tajoli@cineca.it>
Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>