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/get-selects-and-relations-from-object-array.ts

@@ -0,0 +1,53 @@
+import { deduplicate } from "./deduplicate"
+import { isObject } from "./is-object"
+
+export function getSelectsAndRelationsFromObjectArray(
+  dataArray: object[],
+  prefix?: string
+): {
+  selects: string[]
+  relations: string[]
+} {
+  const selects: string[] = []
+  const relations: string[] = []
+
+  for (const data of dataArray) {
+    for (const [key, value] of Object.entries(data)) {
+      if (isObject(value)) {
+        relations.push(setKey(key, prefix))
+        const res = getSelectsAndRelationsFromObjectArray(
+          [value],
+          setKey(key, prefix)
+        )
+        selects.push(...res.selects)
+        relations.push(...res.relations)
+      } else if (Array.isArray(value)) {
+        relations.push(setKey(key, prefix))
+        const res = getSelectsAndRelationsFromObjectArray(
+          value,
+          setKey(key, prefix)
+        )
+        selects.push(...res.selects)
+        relations.push(...res.relations)
+      } else {
+        selects.push(setKey(key, prefix))
+      }
+    }
+  }
+
+  const uniqueSelects: string[] = deduplicate(selects)
+  const uniqueRelations: string[] = deduplicate(relations)
+
+  return {
+    selects: uniqueSelects,
+    relations: uniqueRelations,
+  }
+}
+
+function setKey(key: string, prefix?: string) {
+  if (prefix) {
+    return `${prefix}.${key}`
+  } else {
+    return key
+  }
+}