feat(core-flows,medusa,utils): promotion and campaign create/update endpoint (#6130)

what:

- adds create endpoint for promotions including workflows and endpoint (RESOLVES CORE-1678)
- adds update endpoint for promotions including workflows and endpoint (RESOLVES CORE-1679)
- adds create endpoint for campaigns including workflows and endpoint (RESOLVES CORE-1684)
- adds update endpoint for campaigns including workflows and endpoint (RESOLVES CORE-1685)

packages/utils/src/common/index.ts

@@ -9,6 +9,7 @@ export * from "./errors"
 export * from "./generate-entity-id"
 export * from "./get-config-file"
 export * from "./get-iso-string-from-date"
+export * from "./get-selects-and-relations-from-object-array"
 export * from "./group-by"
 export * from "./handle-postgres-database-error"
 export * from "./is-date"