feat(falukant): add transport cost option to product price calculations

- Updated the `getProductPricesInCitiesBatch` method in FalukantService to accept an options parameter for including transport costs in price calculations.
- Modified the tax calculation logic to conditionally apply transport costs based on the new parameter, enhancing the accuracy of pricing based on regional differences.
- Adjusted the FalukantController to pass the includeTransportCosts option from the request body, improving flexibility in pricing queries.

backend/controllers/falukantController.js

@@ -262,11 +262,17 @@ class FalukantController {
             const body = req.body || {};
             const items = Array.isArray(body.items) ? body.items : [];
             const currentRegionId = body.currentRegionId != null ? parseInt(body.currentRegionId, 10) : null;
+            const includeTransportCosts = body.includeTransportCosts === true || body.includeTransportCosts === 'true';
             const valid = items.map(i => ({
                 productId: parseInt(i.productId, 10),
                 currentPrice: parseFloat(i.currentPrice)
             })).filter(i => !Number.isNaN(i.productId) && !Number.isNaN(i.currentPrice));
-            return this.service.getProductPricesInCitiesBatch(userId, valid, Number.isNaN(currentRegionId) ? null : currentRegionId);
+            return this.service.getProductPricesInCitiesBatch(
+                userId,
+                valid,
+                Number.isNaN(currentRegionId) ? null : currentRegionId,
+                { includeTransportCosts }
+            );
         });
         this.renovate = this._wrapWithUser((userId, req) => this.service.renovate(userId, req.body.element), { blockInDebtorsPrison: true });
         this.renovateAll = this._wrapWithUser((userId) => this.service.renovateAll(userId), { blockInDebtorsPrison: true });