add name Phase_graphics_3d to init

proxtoolbox/Problems/OrbitalTomog/Graphics/__init__.py

-from .Phase_graphics import Phase_graphics
+from .Phase_graphics import Phase_graphics, Phase_graphics_3d
 # from proxtoolbox.Utilities.OrbitalTomog.array_tools import *
 from .complex_field_visualization import complex_to_rgb
 from .stack_viewer import XYZStackViewer, SingleStackViewer
 
-__all__ = ["Phase_graphics", "complex_to_rgb", # 'fourier_interpolate', "roll_to_pos",
+__all__ = ["Phase_graphics", "Phase_graphics_3d", "complex_to_rgb", # 'fourier_interpolate', "roll_to_pos",
            'XYZStackViewer', 'SingleStackViewer']