Custom Sections with multiple elements

[AlexanderJuestel]

Is your feature request related to a problem? Please describe.
Currently, it is only possible to define a straight custom section defined by two points.

Describe the solution you'd like
For industrial purposes, it is sometimes useful to to plot custom sections strinking in different directions such as along roads/tunnels/pipelines or if geological features turn in direction. We should have the possibility to provide a list of points defining the corner points of sections

Describe alternatives you've considered
Multiple sections could be plotted next to each other.

[Japhiolite]

Just as another use-case: With many 2D-seismic profiles being no straight lines, it'd be nice to pick non-straight profiles, for instance to compare the model with interpretations from the respective seismic profiles.