Align Vehicle Models with Velocitas Vehicle Model

[wba2hi]

Is your feature request related to a problem? Please describe.
We should align our Vehicle Model with Velocitas Vehicle Model.

Describe the solution you'd like

• package structure should be aligned: https://github.com/eclipse-velocitas/vehicle-model-cpp/tree/main/include/vehicle_model
• introduce simplified methods to get / set / subscribe data from databroker similar to how it's done in velocitas.
  examples:
  get
  const auto vehicleSpeed = Vehicle.Speed.get()->await().value();
  set
  Vehicle.Cabin.Seat.Row1.Pos1.Position.set(desiredSeatPosition)->await();

Additional context

• Every language has it's own quirks and best practices - we do not aim for an alignment of 100%. However, we should align / be consistent where it makes sense
• Could be done e.g. using optional Kotlin Extensions, the databrokerConnection needs to be provided to get / set method as an argument in this case.