GOF plots: no colors in the legend

[Yuri05]

E.g. check this plot (RE 2.2.363):
https://github.com/Yuri05/TestReport/blob/main/Test_Verapamil/report.md#figure-3-1
Different symbols are properly displayed in the legend, but colours are ignored (all symbols in the legend are black)

[pchelle]

In the configuration plan,
Symbols and legend captions are associated with Groups displayed in the legend captions.
But colors can be associated with the output mappings within each group.
Thus, multiple colors are possible for one symbol

[pchelle]

Different solutions are possible here.

• Do not show the color in the legend (currently done)
• Show the first color from each Output Mapping in the legend
• Show the color in the legend only if there is only one color for the Output Mapping, and show black otherwise

[Yuri05]

In the configuration plan, Symbols and legend captions are associated with Groups displayed in the legend captions. But colors can be associated with the output mappings within each group. Thus, multiple colors are possible for one symbol

hmm, indeed. I just wonder why we define the colour then on the output mapping level and not on the group level.
@pchelle Do you remember the reason?

OK, let's keep it AS IS for now.

[pchelle]

I don't remember why.
The last example I have checked had different mappings due to different observed data sets, but used the same simulation.
Since now we can group the observed data sets together, may be the output mapping can be simplified.

[Yuri05]

to discuss with @TWendl

[Yuri05]

Closing in favor of #1331