Release 1.6.3

• ✨ add XLSX grade export and import to external lecturer pages
• ✨ add SQ JSON export for ÜQ Prüfungen import in CAS Campus
• 🩹 disable slot switching without selection mode

This release adds XLSX exports and grade imports for the external lecturer feature as well as a JSON export for the ÜQ Prüfungen import in CAS Campus.