update translation strings, update german translation

[swurzinger]

• update translation strings in all language files

  • add missing ones
  • remove some obsolete ones, which are not used in the code
  • rename some slightly changed keys
  • fix broken/wrong escape sequences (single quotes have been encoded wrongly)

• update german translation strings

  • sort strings according to english base strings
  • add missing translations
  • fix wrong/faulty translations
  • removed obsolete translations

[what-the-diff]

PR Summary

• Improved Translation for "N/A"
  The translation for "N/A" has been improved by updating it from "N/A" to "N/A".

• Refined Escape Characters in Strings
  The escape characters in various strings have been corrected. For instance, "identifier/namespace" has been changed to "identifier/namespace" and "Product / Service" to "Product / Service".

• Consistency in Translations
  The term "N/D" has been updated to "N/D" to maintain consistency in translations.

• Adjusted Escape Character in Specific Term
  The escape character in "Merge Products On Receipt/Invoice" has been changed to "Merge Products On Receipt/Invoice" for clarity and readability.