Move getVehiclesSource() from QsimConfigGroup somewhere else

[jfbischoff]

The vehicle Source is currently determined by in a config Switch in QSim Config Group.
That said, it is mostly used in PersonPrepareForSimImpl, which is independent of the Mobsim one is using. Qsim uses it additionally in PopulationAgentSource (which is probably the reason why the switch ended up there in the first place).
That leads to the somewhat unintuitive behavior that one has to set a switch in Qsim Config Group, indepent of the Mobsim used. Certainly not a drama, but odd nonetheless.

I would propose moving this Config Setting somewhere else in mid-term. Any ideas what would be a better place? VehiclesConfigGroup perhaps?
@mrieser @Janekdererste @kainagel Feel free to discuss :-)

[mrieser]

PersonPrepareForSim seems to be used by PrepareForMobsimImpl, which is used by (New)Controler.
--> ControlerConfigGroup?

[Janekdererste]

Since it is related to vehicles, why not move it into the vehicle section?

[kainagel]

I think that we use the Controler config group for material that does not fit into any of the other config groups. I think that in this case we can argue that this refers mostly to vehicles. (Also, the vehicles config group is much smaller, so moving it there would balance the number of switches in each category a bit better.) Yet, my intuition is not very strong. You could vote, or flip a coin.