Changes to the parent field of a work item doesn't include appropriate data

Summary

As per this thread, changes to the parent field of a work item record triggers an event to be fired, but the parent data is not present in the payload changes object. We should also include any data about the parent in object_attributes.

Additional Notes

• This update focuses on enhancing the work items experience without altering the legacy epics experience.
• This feature doesn't exist in the legacy experience, but that's an oversight/gap that we need to resolve.