Freight (Carrier): Generalize CarrierJobs

[kt86]

Later it is maybe more generalized and can have 1 or to 2 locations with all the settings (TimeWindow, handlingDuration).
Depending on the number of locations, the jsprit algorithm is chosen: If it is a 1-location job, jsprit uses "Services", if it has 2 locations, it uses "Shipments".

A therefore needed, central Interface is created in #3599.

Maybe something for the hackathon, or the code sprint... but definitely not urgent, but code-breaking.

(This issue was extracted from #3510.)