fix(medusa-plugin-brightpearl): account for shipping prices being tax inclusive (#2536)

**What**
BP plugin was recording total shipping price based on the shipping_method.price; however, this value may be with or without taxes depending on the tax inclusivity setting. This change ensures that the shipping price is calculated correctly.

.changeset/chilled-ads-flash.md

@@ -0,0 +1,5 @@
+---
+"medusa-plugin-brightpearl": patch
+---
+
+fix(medusa-plugin-brightpearl): account for shipping prices being tax inclusive

packages/medusa-plugin-brightpearl/src/services/__tests__/brightpearl.js

@@ -25,6 +25,7 @@ const order = {
     {
       name: "standard",
       price: 12399,
+      subtotal: 12399,
     },
   ],
   payment_method: {
@@ -66,6 +67,7 @@ const krwOrder = {
     {
       name: "standard",
       price: 12399,
+      subtotal: 12399,
     },
   ],
   payment_method: {
@@ -109,6 +111,7 @@ const roundingOrder = {
     {
       name: "standard",
       price: 0,
+      subtotal: 0,
     },
   ],
   discounts: [
@@ -159,6 +162,7 @@ const TotalsService = {
   getShippingMethodTotals: () => {
     return {
       price: 0,
+      subtotal: 0,
       discount_total: 0,
       tax_total: 0,
     }

packages/medusa-plugin-brightpearl/src/services/brightpearl.js

@@ -994,7 +994,7 @@ class BrightpearlService extends BaseService {
           }
         )
         return {
-          price: accum.price + totals.price,
+          price: accum.price + totals.subtotal,
           tax: accum.tax + totals.tax_total,
         }
       }, Promise.resolve({ price: 0, tax: 0 }))