Fix incorrect plotting of mutational profile

[FerriolCalvet]

Currently we were only plotting the relative mutation probabilities of each trinucleotide change, while usually the mutational profile is plotted as the % of SBS of each trinucleotide.

From now on we will be plotting three versions of the plot:

• Same as now, relative mutation probabilities or each trinucleotide change
• % of SBS of each trinucleotide change of the mutations observed in our panel
• % of SBS of each trinucleotide change of the mutations we would observe in one WGS if mutations were occuring with the same probabilities as they occur in our sequenced panel