fea(providers): locking postgres (#9545)

Co-authored-by: Adrien de Peretti <25098370+adrien2p@users.noreply.github.com>

packages/medusa/src/modules/locking-postgres.ts

@@ -0,0 +1,6 @@
+import PostgresLockingProvider from "@medusajs/locking-postgres"
+
+export * from "@medusajs/locking-postgres"
+
+export default PostgresLockingProvider
+export const discoveryPath = require.resolve("@medusajs/locking-postgres")