[EMSUSD-9] Respect upAxis metadata

The upAxis setting in the metadata (https://graphics.pixar.com/usd/docs/api/group___usd_geom_up_axis__group.html) is currently ignored, meaning that any scene which has it's upAxis set as Z will be rotated.

Usdview respects this, and rotates the geometry accordingly, to always show the upAxis as "up".

The KitchenSet is a good example of an asset with upAxis=Z

Start by locating where the plugin reads USD scene metadata and handles scene orientation; compare the expected behavior with usdview using the KitchenSet asset, whose upAxis is Z. Done means scenes with Z upAxis are oriented correctly rather than rotated incorrectly.

Written by the indexing model from the issue text.