Person vehicle types attribute

[rakow]

Introduces a vehicleTypes attribute in persons and a new PersonVehicleTypes class that allow to store mode specific vehicle types. Use VehicleUtils.insertVehicleTypesIntoAttributes to set this attribute.

This class is similar to the existing PersonVehicles, but instead of the id it allows to store a mode specific vehicle type.
This attribute is completely optional, and the current behavior is not changed, unless this attribute is set. Setting the type explicitly is useful for use-cases where mode specific vehicle types are not sufficient, and the types need to be further differentiated on a per-person basis.

Closes #2801 .

[rakow]

@mrieser: I think minibus and dmc contrib are still failing undeterministicly.