Importing Postman collection does not retain order of folders

[DanaEpp]

When importing a Postman collection that contains several folders, it appears that Bruno reorders them.

This breaks the order of precedence for the test plan.

Expected behavior: The folders should be imported in the same order as what is listed in the items array in the JSON file.

[DanaEpp]

This sort of relates to #1568. We need to keep the order on import, and then support drag-and-drop to reorder if needed.