Sympy Plot Backends v2.2.0

What's Changed

• Improved complex domain coloring and added plot_riemann_sphere.

• Added imagegrid keyword argument to plotgrid.

• Enabled support for plotting indexed objects.

• Implemented colorbar keyword argument to show/hide colorbar.

• Implemented show_in_legend keyword argument to show/hide a specific
  series on the legend of a plot.

• Improved logic about legend.

• Fixed bug with PlotlyBackend when creating 3D analytic landscapes.