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/src/helpers/test-request.js

@@ -1,3 +1,4 @@
+import { MockManager } from "medusa-test-utils"
 import { createContainer, asValue } from "awilix"
 import express from "express"
 import cookieParser from "cookie-parser"
@@ -28,6 +29,7 @@ container.register({
   logger: asValue({
     error: () => {},
   }),
+  manager: asValue(MockManager),
 })
 
 testApp.set("trust proxy", 1)