Need ability to save scanned spatial mesh data (HoloToolkit parity)

[david-c-kline]

Overview

HoloToolkit enabled saving scanned spatial mesh data (via a network connection back to Unity). MRTK should have a similar (possibly different process) to do the same.

[david-c-kline]

MRTK v2 is receiving support for using 3D models in the editor to simulate the spatial mesh source (#5128).

It supports loading .room files. The recommendation for acquiring mesh data from physical spaces is to download it from the Windows Device Portal (.obj file format).