Allow dynamic change of special JuPedSim polygons

[RNippold]

Currently, SUMO creates polygons as copies during initialization, so there is no reference to the original polygons. Therefore, dynamic changes (e.g., via TraCI) to polygon parameters cannot be passed on (e.g., to JuPedSim).
I would therefore like to suggest initializing polygons as references to enable dynamic interaction.

[namdre]

Needs more details on what is currently passed to JuPedSim (I was under the impression that it's only raw geometries). Is this about modifying geometries at runtime or about supplemental data associated with polygons (i.e. sumo <param> elements)?

[behrisch]

@RNippold I decided to make the whole jupedsim polygon stuff dynamic because otherwise we would get dangling references whenever someone decides to remove the polygon dynamically. It would be great if you could add some tests about adding, removing and changing parameters for influencer and vanishing_area via traci.