chore: Translate transifex_input.json in de_DE

50% of minimum 50% translated source file: 'transifex_input.json'
on 'de_DE'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

translations/frontend-platform/src/i18n/messages/de_DE.json

@@ -0,0 +1,4 @@
+{
+  "unexpected.error.message.text": "An unexpected error occurred. Please click the button below to refresh the page.",
+  "unexpected.error.button.text": "Erneut versuchen"
+}