Layered Surface Segmentation Feature

In this branch, the feature for demostrating Layered Surface Segmentation based on the slgbuilder package, is implemented. The feature is divided into a functional file, visualisation file and a gui file, all named Layers2d.

qim3d/__init__.py

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 """qim3d: A Python package for 3D image processing and visualization.
 
 The qim3d library is designed to make it easier to work with 3D imaging data in Python.