Add plot function for MOEAs

[jakobbossek]

We need a nice function to visualize the Pareto front (and/or the Pareto set).
Use ggplot2 by default for 2D and offer plotly/scatterplot3d for 3D visualization.

[berndbischl]

would that operate on the optpath? paramhelpers has that to some extend

[jakobbossek]

No. The package does not manage the population within the optpath; it is optional for logging.
Maybe in v2.

[berndbischl]

But if you can optionally log during the algorithm into the path you can surely do that at the end? Which us also non performance critical?

And I don't really see the difference between what we would like to see in visualization of fronts compared to what you want to see. So sounds like completely duplicated code.