Descendant deletion sync bugs

[edschema]

Description

• Sync not working for syncs where the only change is deleted descendant
  Add a subsection to a course with units and components. Delete one of the components as the only change.
  The sync modal is stuck in a loading state.

• Sync not appearing for deleted components
  Add a section with subsections, units, components. Delete component as the only change. publish at the unit level.

This bug is not consistent. sometimes sync appears on library updates, sometimes it does not. When it does appear, sync does not work.

[navinkarkera]

@edschema This issue is ready for AC testing on the sandbox

[bradenmacdonald]

Looks like this was fixed, so I'm going to close. Re-open if it's found again during testing.