feat: Add supported currencies to store model (#6562)

I ultimately went with having a flat list of settings for the store. It wouldn't be very difficult to change it if we wish to do so, but for now this keeps the codebase simpler

packages/store/integration-tests/__fixtures__/index.ts

@@ -2,6 +2,7 @@ import { StoreTypes } from "@medusajs/types"
 
 export const createStoreFixture: StoreTypes.CreateStoreDTO = {
   name: "Test store",
+  supported_currency_codes: ["usd", "eur"],
   default_sales_channel_id: "test-sales-channel",
   default_region_id: "test-region",
   metadata: {

packages/store/integration-tests/__tests__/store-module-service.spec.ts

@@ -19,6 +19,7 @@ moduleIntegrationTestRunner({
           expect(store).toEqual(
             expect.objectContaining({
               name: "Test store",
+              supported_currency_codes: expect.arrayContaining(["eur", "usd"]),
               default_sales_channel_id: "test-sales-channel",
               default_region_id: "test-region",
               metadata: {