Replaces MongoDB support with PostgreSQL (#151)

- All schemas have been rewritten to a relational model
- All services have been rewritten to accommodate the new data model
- Adds idempotency keys to core endpoints allowing you to retry requests with no additional side effects
- Adds staged jobs to avoid putting jobs in the queue when transactions abort
- Adds atomic transactions to all methods with access to the data layer

Co-authored-by: Oliver Windall Juhl <oliver@mrbltech.com>

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

@@ -71,7 +71,7 @@ class EconomicService extends BaseService {
     let order_lines = []
     // Find the discount, that is not free shipping
     const discount = order.discounts.find(
-      ({ discount_rule }) => discount_rule.type !== "free_shipping"
+      ({ rule }) => rule.type !== "free_shipping"
     )
     // If the discount has an item specific allocation method,
     // we need to fetch the discount for each item