show_legend = false removes not only the legend but also the colorbar in an erp plot

[jschepers]

In my effects plot, setting show_legend = false not only removed the legend (as intended) but also the colorbar.

Example:

plot_erp(
           effects(Dict(:condition => ["car", "face"], :continuous => -5:5), m);
           mapping = (; color = :continuous, linestyle = :condition, group = :continuous),
           categorical_color = false,
           axis = (xlabel = "Time [s]", ylabel = "Amplitude [μV]"),
           layout = (;show_legend=false),
       );

[vladdez]

we need to depricate show_legend

[vladdez]

#237 not deprecated but handled