Take Fix cost into account when switch vehicles

[sj1ang]

It seems that jsprit does not calculate the fix cost difference when switch a new vehicle in bestInsertion. For example, if two vehicle types with the same cost params except for the fix cost ($100 vs $0)are configured in the puzzle, vehicle with $100 fixed cost wouldn't be replaced by vehicle with $0 in the final solution.
I tried calculate the difference between two vehicles in com.graphhopper.jsprit.core.algorithm.recreate.ServiceInsertionCalculator.ServiceInsertionCalculator, the problem seems fixed.