Enhance SaleSection component to group and display transport data

- Updated SaleSection.vue to group running transports by relevant attributes, improving data organization and readability.
- Added a new computed property to calculate vehicle counts and total quantities for grouped transports.
- Introduced a new column in the UI to display the count of vehicles associated with each transport group.
- Updated German localization file to include translation for 'runningVehicleCount', enhancing user experience for German-speaking users.

frontend/src/i18n/locales/de/falukant.json

@@ -205,6 +205,7 @@
                 "runningTarget": "Ziel",
                 "runningEta": "Ankunft",
                 "runningRemaining": "Restzeit",
+                "runningVehicleCount": "Fahrzeuge",
                 "runningDirectionOut": "Ausgehend",
                 "runningDirectionIn": "Eingehend"
             },