Implement empty transport feature in DirectorInfo component

- Added functionality to allow directors to initiate empty transports without products, enhancing logistics management.
- Introduced a new transport form in the DirectorInfo component, enabling selection of vehicle types and target branches.
- Updated the i18n localization files to include new translations for the empty transport feature.
- Enhanced the BranchView to pass vehicle and branch data to the DirectorInfo component, ensuring proper functionality.
- This update aims to improve user experience and streamline transport operations within the application.

backend/models/falukant/data/transport.js

@@ -15,11 +15,11 @@ Transport.init(
     },
     productId: {
       type: DataTypes.INTEGER,
-      allowNull: false,
+      allowNull: true, // Nullable für leere Transporte (nur Fahrzeuge bewegen)
     },
     size: {
       type: DataTypes.INTEGER,
-      allowNull: false,
+      allowNull: true, // Nullable für leere Transporte (nur Fahrzeuge bewegen)
     },
     vehicleId: {
       type: DataTypes.INTEGER,