EGN before depth and shadow segmentation

[CameronBodine]

Can EGN improve depth and shadow segmentation?

Current workflow:
depth segmentation -> shadow segmentation -> EGN correction

Both water column removal and shadow removal are optional pre-processing steps for EGN. This allows export of corrected WCP (e.g., fish counts or veg detection) or brightening returns in the far field.

Since EGN doesn't require pre-processing, raw sonar returns could be first corrected before segmenting depth and shadows. This may improve model inference.

New workflow option (in addition to existing workflow):
EGN -> depth segmentation -> shadow segmentation