Tutorial proposal: Probes, paths, slices

[PProfizi]

📝 Description of the tutorial

Proposing a dedicated section for creating probes, paths and slices.

This would show how to use the geometry module Point, Line, and Plane classes to create a point probe, a linear path, or a planar slice.
These would show how to perform mapping, or better yet, we would create helpers on these classes to do the necessary operations themselves.

• Point -> probe: quite simple, create a Point, probe a Field or a FieldsContainer at the coordinates.
• Line -> path: already have examples on that, used to be in plotting, should be here. They only showed how to do a path comprised of points though. Maybe we could improve it by mapping onto actual line elements.
• Plane -> slice: a lot missing here. Not feasible with the current tools available.

The cut would be in another dedicated section.
Streamlines would be in their dedicated section.