feat: event aggregator (#6218)

What:
- Event Aggregator Util
- Preparation for normalizing event in a new format (backward compatible with the current format)
- GQL Schema to joiner config and some Entities configured
- Link modules emmiting events

.changeset/sharp-rocks-retire.md

@@ -0,0 +1,13 @@
+---
+"@medusajs/event-bus-local": patch
+"@medusajs/event-bus-redis": patch
+"@medusajs/link-modules": patch
+"@medusajs/modules-sdk": patch
+"@medusajs/inventory": patch
+"@medusajs/product": patch
+"@medusajs/medusa": patch
+"@medusajs/types": patch
+"@medusajs/utils": patch
+---
+
+Feat: Event Aggregator