Feat/mikro orm based linkable (#7944)

**What**
- Generate simple linkable for mikro orm based modules 
- fix module util
- fix joiner config builder
- fix define link relationship extension
- fix migrations not loading custom links

packages/modules/link-modules/src/services/dynamic-service-class.ts

@@ -14,7 +14,7 @@ export function getModuleService(
   // database config if any fields are provided.
   if (!isDefined(joinerConfig_.extraDataFields)) {
     joinerConfig_.extraDataFields = Object.keys(
-      databaseConfig.extraFields || {}
+      databaseConfig?.extraFields || {}
     )
   }