feat(medusa, types, utils, core-flows, order) request & accept order transfer (#10106)

**What**
- add request order transfer workflow
- add admin endpoint for transferring an order to a customer
- accept order transfer storefront endpoint
- accept transfer workflow
- changes in the order module to introduce new change and action types

---

**Note**
- we return 400 instead 409 currently if there is already an active order edit, I will revisit this in a followup
- endpoint for requesting order transfer from the storefront will be added in a separate PR

---

RESOLVES CMRC-701
RESOLVES CMRC-703
RESOLVES CMRC-704
RESOLVES CMRC-705

packages/modules/order/src/utils/actions/index.ts

@@ -13,3 +13,4 @@ export * from "./ship-item"
 export * from "./shipping-add"
 export * from "./shipping-remove"
 export * from "./write-off-item"
+export * from "./transfer-customer"

packages/modules/order/src/utils/actions/transfer-customer.ts

@@ -0,0 +1,19 @@
+import { ChangeActionType, MedusaError } from "@medusajs/framework/utils"
+import { OrderChangeProcessing } from "../calculate-order-change"
+import { setActionReference } from "../set-action-reference"
+
+OrderChangeProcessing.registerActionType(ChangeActionType.TRANSFER_CUSTOMER, {
+  operation({ action, currentOrder, options }) {
+    currentOrder.customer_id = action.reference_id
+
+    setActionReference(currentOrder, action, options)
+  },
+  validate({ action }) {
+    if (!action.reference_id) {
+      throw new MedusaError(
+        MedusaError.Types.INVALID_DATA,
+        "Reference to customer ID is required"
+      )
+    }
+  },
+})