Fix broken hydration in vendor lookup metadata by using a new API endpoint in VendorServices (fetch vendor by vendor ref). This new endpoint is only available starting in VendorServices 1.6.3, so it is recommended to update to that version. If VendorServices is not updated, then the lookups will continue to behave as they do currently - they will not be any more broken than they are today.
Make the vendor field read-only in the inventory location update form (matching existing backend validation)