[USDU-275] Adds testcase for checking if export keeps the original data structure

[lee-aandrew]

Purpose of this PR

Ticket/Jira #:
[USDU-275] & [USDU-279]

Testing

ExportAsUsdz_DataStructureKeptOnImport:

1. Imports a known USDA file
2. Exports it as a UDSZ file
3. Import the USDZ file
4. Check if the imported USDZ file maintains the same game object structure as the initially imported USDA file

Complexity:
1

Halo Effect:
1

Additional information

Note to reviewers:

Reminder:

• Add entry in CHANGELOG.md (if applicable)

[vickycl]

Is there a reason for making this test a Runtime test? I can't think of a reason not to, but it does seem like exporting in EditMode is a far more common use case, so I'm curious :)