`--no-total` and `--legend-cutoff` options like `sumo`

[kavanase]

I think CLI options --no-total (to hide the solid black line of the total XPS spectrum) and --legend-cutoff options as available with sumo-dosplot would be nice additions to the functionality of Galore.

They would be useful options to improve the clarity of output XPS plots, as often the orbital character of the XPS peaks are hidden by the solid black line (if only a single orbital contribution dominates at a given energy range, as is typical) and also the legend often includes many orbital contributions that have negligible contributions to the XPS spectrum.

For example: