Change to vedo for 3D visualisation

[DSimonne]

Could follow these scripts and implement them:

• https://github.com/marcomusy/vedo/blob/master/examples/pyplot/isolines.py
• https://github.com/marcomusy/vedo/blob/master/examples/pyplot/plot_density4d.py
• https://github.com/marcomusy/vedo/blob/master/examples/volumetric/app_isobrowser.py
• https://github.com/marcomusy/vedo/blob/master/examples/volumetric/isosurfaces.py
• https://github.com/marcomusy/vedo/blob/master/examples/volumetric/slicer1.py