Extend shape features

[ckmah]

To properly handle more complex feature calculations for Shapes, shape features need to accommodate:

• features per cell
• features for subcellular shapes
  • 1 to 1 mapped shapes e.g. single nuclei
  • many to 1 mapped shapes e.g. multiple nuclei, organelles
• keep in mind: output should be easy to interface (store in joined tables) with point features (also store in tables? aligned to instance_key)

Potential designs:

• keep current functional wrappers for cell features
  • pros: least code change
  • cons: may become harder to track/enforce how output is stored spatialdata object
• use OOP design similar to PointFeatures implementation
  • pros: PointFeatures can more easily infer attribute names for shape features they depend on
  • cons: significantly more code