added third maximal mass for ovc hevs and ng vehicles

added helper class in vecto vehicle test to look up values from linear curves with multiple sections

implemented this check in the base class for all components

do not require a hybrid controller, so the test-powertrain class can be used for other purposes as well

remove initialize method in gearbox that takes a gear as argument and issues a dry-run request with a different gear.
this approach caused errors because the internal 'previous state' of components might be modified.
instead, a separate simple test-powertrain is used to calculate the necessary values without altering the state of the actual powertrain

(cherry picked from commit 571fe081)