image: change_orientation() to extend <3D images to 3D when changing orientation (#2006)
image: change_orientation() to extend <3D images to 3D when changing orientation (#2006)

Former-commit-id: 968e272656cf2056052d855d9a26d73ede89a1fd
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox