- Created models for DB and DTOs: StayExportFile
- Added required db migrations.
- Added StayExportService and StayExportServiceFactory for stay exporting services.
- Added configuration options required for StayExport.
- Added new entity "StayEntry" to log stays of guests.
- Added pages for StayEntry management (List and creation).
- New DataList for PaymentMethods.
- Other general changes and improvements.