Add openmc-plotter to tutorials

[aprilnovak]

Reason

There's so many awesome features in the openmc-plotter, especially with the upcoming mesh overlay capability.

Design

• We should add info on how to use the openmc-plotter (or at least links to it) for Cardinal simulations, to the Cardinal website
• Perhaps we can auto-install the plotter as part of the Cardinal build?

[pshriwise]

I wonder if adding some optional dependencies to the OpenMC Python package itself makes sense, similar to

pip install .[test]

for the test dependencies, we could include a vis option that will install the vtk Python module along with the plotter utility and its dependencies.

pip install .[test,vis]

Then it's just a matter of including those optional Python dependencies for the plotter. It's not quite what that packaging capability is intended for, but it might simplify things for users in this case. It's not hard to do it using standard methods I suppose.