feat: Implement general contract booking orders functionality

- Add DTOs for creating booking orders and viewing contract quantities.
- Create entities for booking orders and booking order lines.
- Implement service for managing general contract operations, including activation after payment and retrieving quantity lines.
- Develop UI components for contract detail and list pages, including order placement dialog.
- Integrate API service for booking orders, enabling listing and creating orders against contracts.
- Enhance contract status display and quantity pool visualization in the UI.

apps/edr-freight-api/src/modules/train-scheduling/train-scheduling.service.ts

@@ -1880,7 +1880,7 @@ export class TrainSchedulingService {
       origin: booking.originYard?.label ?? booking.originYard?.code ?? 'Unknown origin',
       destination:
         booking.destinationYard?.label ?? booking.destinationYard?.code ?? 'Unknown destination',
-      preferredDepartureDate: booking.scheduledDate.toISOString(),
+      preferredDepartureDate: booking.scheduledDate?.toISOString() ?? null,
       status: booking.status,
     };
   }