fix(append pipeline): Adding additional filter/custom code to pipeline

[ayenpure]

This PR addresses the feature request from
#191

[ayenpure]

@jourdain This is meant to be just the initial check-in to demonstrate what we chatted about.
The Jupyter Lab example works, but I wanted to verify that this is what we had in mind.
If this feels alright, I can make changes to other explorers and add the method add_to_pipeline to the constructor.

[jourdain]

Yes that is what I had in mind. Spiros told be that it is better to use vtkGeometryFilter instead of vtkDataSetSurfaceFilter.
It is faster when using stdthread for vtkSMP.

[ayenpure]

@johnkit The Jupyter Lab example I added with this PR has an example of extending the pipeline.
It addresses your use case -- let me know what you think.

[ayenpure]

@jourdain ready for review

[jourdain]

Need to skip examples/jupyter/pflotran_extend_pipeline.ipynb:35: fo ==> of, for, to, do, go for the CI

[jourdain]

https://github.com/Kitware/pan3d/blob/main/.codespellrc

[jourdain]

You just need to fix the CI now.