Enhancement: dose normalised plots / data

[js3110]

Description

Linked to #127
Option for user to select dose normalisation which then gives plots (line plots & box plots) with conc/dose on the axis.

Definition of Done

The requirements for the feature to be complete:

• option to select dose normalised on plots
• norm_dose calculated correctly and shown in plots

[Gero1999]

Whoever ends up doing this:

Any post PKNCA presult (i.e, boxplots, summary statistics...) will already include this option when the parameter is requested by the user. So no need for additional implementations. Mean plots on the other hand are prePKNCA!