Translate Modules involved into German.

Problem/Motivation

Sice this is something that will become the home of Drupal's German Community we should have all modules involved translated into German.

Let's reference the existing issues in the project DE here and create new issues so that we are sure that the user interface of the Druipal Centre is available in German. In addition, we can keep the translations of the installed modules up to date in this way.

Steps to reproduce

Proposed resolution

✅ Check wich Modules are used
Create new issue in de if there isn't one, yet.
Reference that issues with this one as parent Issue.

Remaining tasks

✅Check Modules used snf build up a list.
❌ Create one Issue per Module in De.
❌ Reference each Issue here.
❌ Update translations.
❌ reference translators properly in every issue a particular translatior has at least one confirmed string.
❌ Close this issue after sub Issues are finished.

User interface changes

API changes

Data model changes