Implement Curvature-Based Mesh Cropping in Visualizer

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### Proposed new feature or change

**Description:**
Currently, in the Open3D Visualizer, the "C" key allows users to crop a selected shape by drawing a line between two points. However, this approach results in a cut with visible edges, which may not always be desirable for certain applications.

**Proposed Solution:**
I propose enhancing the cropping functionality in the Open3D Visualizer to support curvature-based mesh cropping. Instead of drawing a straight line between two points, the cropping operation should create a smooth curvature between the selected points, resulting in a more visually appealing cut without visible edges.

**Potential Implementation:**
To implement this feature, we could explore algorithms for mesh slicing that preserve the smoothness of the mesh surface while removing the selected portion. This could involve adapting existing mesh slicing algorithms or developing a new approach specifically tailored for curvature-based cropping in the Open3D Visualizer.

**Benefits:**
- Provides users with a more intuitive and visually pleasing way to crop meshes in the Open3D Visualizer.
- Enhances the quality of cropped meshes by removing visible edges and preserving surface curvature.
- Expands the capabilities of Open3D for mesh processing tasks, particularly in applications where smooth cuts are important, such as mesh editing and visualization.

**Additional Notes:**
It's essential to ensure that the implementation of curvature-based cropping maintains compatibility with existing features and workflows in the Open3D Visualizer. User feedback and contributions are encouraged throughout the development process to ensure the feature meets the needs of the community.

### References

Nr

### Additional information

Nr