Feature Request: Natively use magnitude of multicomponent data

[MatthewFlamm]

I'd like to request an easy to use way to utilize the magnitude of multicomponent data in ipygany. Something like this where the velocity data has multiple components and norm is an optional argument.

colored_mesh = IsoColor(mesh, input='velocity', norm=True)

Right now, the only method I can come up with is to add the magnitude as a separate component or separate data. It would be useful in pyvista to avoid having to create another data array for ipygany. This arose in pyvista/pyvista#1387 (comment).