fix english I18n strings & externalize all strings

[richardtreier]

The PR #756 introduced i18n:

• The PR was alive too long.
• Translation required the SharedModule refactoring that was prepared.
• Any changes were merge conflicts, especially wording changes.

Thus we need to properly check the UIs now, @illfixit

• Check the fast-tracked PR for open discussions
  • Internationalize the UI and add a German localization #756
  • No wording changes were intended, so if any wording changes were not taken over properly due to the merge conflicts, we should recover them
• Some english translations are missing after the merging
• All pages need to be eyeballed for missed wording changes that @richardtreier might have missed resolving merge conflicts
• All strings added in changes between need to be extracted (See https://github.com/thiagocordeirooo/generate-translation-vscode)
• Ignore the german translation until we have collected all keys (separate issue)
• Consider transforming the keys into a format they can be found with Ctrl+F (no points)
• Consider moving keys where they belong, e.g. splitting Asset List Page and Asset Metadata