split lung fields into quadrants

As part of post-processing, split each lung field into quadrants.

Come up with a reasonable geometric (not anatomical) method for doing this.

The quadrants should resemble the quadrants used for air trapping and fibrosis severity scoring used in e.g. [this paper](https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10975/109750H/LungAIR--an-automated-technique-to-predict-hospitalization-due-to/10.1117/12.2508006.short?SSO=1&tab=ArticleLink):


This is a feature extraction step, so there should be a way to visualize the quadrants in the xray features view. Perhaps markups for the quadrant boundary, or segments.

No files or tests are named. Start by locating the post-processing code and the X-ray features view, then establish how quadrant boundaries or segments can be visualized; done means each lung field is split into geometric quadrants and those quadrants are visible in the features view.

Written by the indexing model from the issue text.