Tutorial on using ellipsoid actor to visualize tensor ellipsoids for DTI

[tvcastillod]

This PR consists of a tutorial that is intended to show two ways of displaying diffusion tensor ellipsoids for DTI visualization. The first is using the basic tensor_slicer actor which allows us to slice many tensors as ellipsoids, and the second with the generic ellipsoid actor I'm currently working on (fury-gl/fury#791), which can be used to display different amounts of ellipsoids. The idea is to show the use that can be made of the ellipsoid actor in the visualization of diffusion tensor ellipsoids, compared to the tensor_slicer actor, contrasting visual quality and the amount of data that can be rendered.

I still working on this, it is not ready for review yet.

[ganimtron-10]

Hey @tvcastillod, I tried out the tutorials and they are fabulous, the visualization looks beautiful.

[codecov[bot]]

Codecov Report

Merging #818 (8e97473) into master (2bba1b9) will decrease coverage by 0.04%. Report is 57 commits behind head on master. The diff coverage is n/a.

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see 3 files with indirect coverage changes