No such DDMStructure expection when deleting a structure that's being referenced by a display page

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.X, Master
• Component/s: ~[Archived] WCM
• Labels:
  • 7.1-must
  • NAT
• Fix Priority: 5
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/60007

1. Go to Content > Web Content > Structures
2. Add a structure
3. Go to Build > Pages > Display Pages
4. Create a Display Page for the structure in step 2
5. Delete the structure

Actual result: The structure can be deleted. Thus, when navigating to display pages, a DDMStructure error is thrown in the console
Expected result: The structure cannot be deleted