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

packages/utils/src/common/camel-to-snake-case.ts

@@ -1,2 +1,2 @@
 export const camelToSnakeCase = (string) =>
-  string.replace(/[A-Z]/g, (letter) => `_${letter.toLowerCase()}`)
+  string.replace(/([a-z])([A-Z])/g, "$1_$2").toLowerCase()