[MAYA-114589] Outliner: Cannot collapse when parented within an unloaded group

[gracekumagai]

Describe the bug
When an object is parented to an unloaded group, the object's new parent cannot be expanded or collapsed. The outliner can be refreshed by collapsing and re-expanding the parent's parent (and now, we can see all the children of the unloaded group).

Steps to reproduce
Steps to reproduce the behavior:

1. Open kitchen_set_instanced
2. Unload |Kitchen_set_instanced|Kitchen_set_instancedShape,/Kitchen_set/Props_grp/Ceiling_grp
3. Parent |Kitchen_set_instanced|Kitchen_set_instancedShape,/Kitchen_set/Props_grp/West_grp/Ball_1 to |Kitchen_set_instanced|Kitchen_set_instancedShape,/Kitchen_set/Props_grp/Ceiling_grp

Expected behavior
We would expect the unloaded parent to be able to be collapsed and expanded.

This ticket is related to #1543. We would expect to see unloaded prims in the outliner (and all the children of unloaded groups). Moving an object to an unloaded group should not change whether the group can be collapsed/expanded.

Attachments
Repro steps:

Specs (if applicable):
OS (Linux 64 bit)
Maya USD: dev at 4710d36
Pixar USD: dev at 96c5a3f
Maya 2022.update2

[wtelford]

@santosg87 Can you bring this one internal please.

[gracekumagai]

Hey @santosg87, I tested this again today and it looks like it has been resolved with #1543. Feel free to close it out if there isn't any other tracking needed on your end - thanks!