Add Plot recipe for A/E ctc

[fhagemann]

Plotting code for now (very much inspired by the energy_ctc calibration in #67):

# This should become a plot recipe at some point
let aoe_final = ljl_propfunc(result.func).(hit_cal), _aoe = ljl_propfunc(result_correction.func).(hit_cal), _qdrift_e = hit_cal.qdrift ./ hit_cal.e_cusp
    sel = abs.(aoe_final) .< 100 #.&& mask
    plot(fit(Histogram, _aoe[sel], -9:0.1:9), fill = true, xlims = (-9,5), color = :darkgrey, subplot = 1, link = :x, framestyle = :semi, size = (1000,1000), margins = (0,:mm), layout = (2,1), grid = false, st = :stepbins, left_margin = (5,:mm), right_margin = (5,:mm), bottom_margin = (-4,:mm), label = "Before correction")
    plot!(fit(Histogram, aoe_final[sel], -9:0.1:9), fill = true, xlims = (-9,5), alpha = 0.5, color = :purple, subplot = 1, link = :x, framestyle = :semi, size = (1000,1000), margins = (0,:mm), layout = (2,1), grid = false, st = :stepbins, left_margin = (5,:mm), right_margin = (5,:mm), bottom_margin = (-4,:mm), label = "After correction", legend = :topleft, ylabel = "counts / 0.1")
    plot!(kde((_aoe[sel], (_qdrift_e)[sel])), subplot = 2, c = :binary, colorbar = :none, st = :line, fill = true, label = "After correction", yformatter = :plain, link = :x)
    plot!(kde((aoe_final[sel], (_qdrift_e)[sel])), subplot = 2, c = :plasma, link = :x, framestyle = :semi, colorbar = :none, st = :line, fill = false, label = "After correction", yformatter = :plain, xlims = (-9,5), ylims = (0,11), ylabel = "Eff. Drift time / Energy (a.u.)")
    plot!(xlabel = "A/E classifier", xtickfontsize = 12, xlabelfontsize = 14, ylabelfontsize = 14, ytickfontsize = 12, legendfontsize = 12, foreground_color_legend = :silver, background_color_legend = :white, fmt = :png)
end

Originally posted by @fhagemann in #87 (comment)

This should become a plot recipe at some point.