feat: Fulfillment module basic structure (#6319)

**What**
Scafold the fulfillment module basic structure

**Bonus**
Simplified module scaffolding with new factories and less directories to manage
- mikro orm connection loader factory
- initialize factory

FIXES CORE-1709
FIXES CORE-1710

packages/fulfillment/mikro-orm.config.dev.ts

@@ -0,0 +1,8 @@
+import * as entities from "./src/models"
+
+module.exports = {
+  entities: Object.values(entities),
+  schema: "public",
+  clientUrl: "postgres://postgres@localhost/medusa-fulfillment",
+  type: "postgresql",
+}