itkwidgets.view crashes when spacing is set in vtkimage

[cchriste]

Use pyvista.Plotter instead.

[cchriste]

# a helper function that converts shapeworks Image object to vtk image
def sw2vtkImage(swImg, verbose = False):
            
    # get the numpy array of the shapeworks image
    array  = swImg.toArray()
    
    # the numpy array needs to be permuted to match the shapeworks image dimensions
    array = np.transpose(array,(2,1,0))
    
    # converting a numpy array to a vtk image using pyvista's wrap function
    vtkImg = pv.wrap(array)
    
    if verbose:
        print('shapeworks image header information: ')
        print(swImg)

        print('\nvtk image header information: ')
        print(vtkImg) 
    
    return vtkImg

img = sw.Image('./../../Data/ellipsoid-v2/segmentations/ellipsoid_07.nrrd')
img.setSpacing([0.2,0.2,1])
vtkimg = sw2vtkImage(img,True)

# set spacing ***
vtkImg.spacing = img.spacing()
# Spacing:	2.000e-01, 2.000e-01, 1.000e+00

# this crashes when spacing is changed
view(vtkimg)

itkwidgets.view crashes when spacing is changed, but works fine if not.
pyvista works and displays spacing correctly.

[cchriste]

related to #899

[cchriste]

Closing since issues will go away for us when #1186 is complete.