Issue 47: 3D Viz Next Steps

[davramov]

I am starting this as a draft PR for the features outlined here: #47

This initial commit includes:

• a small 11MB scan for testing (examples/tomo_scan.h5)
• downsampling methods using Torch and OpenCV (orchestration/flows/bl832/downsample.py)
  • For small datasets (~11MB), Torch/OpenCV performs similarly (4 seconds)
  • For large datasets (~7GB), OpenCV works well, however, Torch appears to run into a memory issue (at least on my laptop) which prevents some of the images from downsampling correctly (exchange/data). To address this, I include a memory check, enabling Torch chunking. This slows down the downsampling (OpenCV: 80 seconds vs Torch: 123 seconds), but at least it works. I am keeping both versions here in case one works better in production.