Changing the level of a parent Goal leaves parent goal ID in children.

Issue Summary

If a user changes the level of a parent goal to a status where it can no longer be a parent, the child goals retain and reports the former parent goal's ID in the API and Enterprise Insights as their current parent ID.

This is reproducible on Data Center: Yes

Steps to Reproduce

1. Create a Goal at the Long Term Strategy level. (Goal A)
2. Create a Goal at the Yearly Goal level and set its parent as Goal A. (Goal B)
3. Change Goal A's level to Yearly Goal and save.
4. Perform a GET with the API on Goal B or look at Goal B's Parent ID in Enterprise Insights.

Expected Results

Goal B's Parent ID is set to 0, identifying it as an orphan in reporting.

Actual Results

Goal B's Parent ID is Goal A's ID.

Workaround

Manually opening each child goal and saving it without selecting a new parent will reset the Parent ID to 0 as expected.