ZnDraw visualizer

[Frieda95]

Fixes #4961

Description of changes:

• ZnDraw incorporated in charged system, polymers, and Lennard-Jones tutorials

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[jngrad]

@Frieda95 The requested ZnDraw features are now available on the main branch. You can avoid the merge conflicts and continue your work by running these commands:

git fetch upstream python
git branch -m zndraw_visualizer zndraw_visualizer_old # rename branch
git checkout -b zndraw_visualizer upstream/python # create fresh branch from main
git cherry-pick 35e061759 # carry over only the tutorial changes

[Frieda95]

ZnDraw at present doesn't allow multiple servers. So its not incorporated in the Lattice Boltzmann tutorial, which requires simultaneous visualization of Langevin dynamics and hydrodynamic systems.

[jngrad]

Thanks!