feat: make boarding point price levelling switchable

config/services.yaml

@@ -185,6 +185,10 @@ services:
         arguments:
             $retentionBufferDays: '%travel_snapshot_retention_buffer_days%'
 
+    App\BusProNet\XmlParser\TravelParser:
+        arguments:
+            $levelBoardingPointPrices: '%env(bool:APP_BPN_LEVEL_BOARDING_POINT_PRICES)%'
+
     App\Service\TravelDataProvider:
         arguments:
             $logger: '@monolog.logger.core'