steeringForceFactor + steeringForceIgnoresSpeed

This PR does four significant things:

downForce has been renamed to steeringForceFactor, otherwise retaining its same functionality* (*See below)
steeringForceIgnoresSpeed, switches handling behavior to ignore the vehicle's current velocity.
When above boolean is true, ~~downForce~~ steeringForceFactor directly controls the vehicle's turningForce instead of it being influenced by speed and steeringForceFactor.
slip_understeer, current steering angle - turningForce (if the vehicle cannot turn at all this returns 1.0, otherwise everything between 0.0)

But why?

Some pack authors may find the current behavior of downForce/overSteer/underSteer to offer less control over their vehicle's handling than wished. This is especially noticeable because at low speeds, downForce has little to no effect on vehicle handling. However this pull request seeks to alleviate that by retaining this behavior by default whilst offering an alternative. As ~~downForce~~ steeringForceFactor can be variableModified, this results in more customizable vehicle behavior through the use of clever VMs.

Other stuff

downForce has technically been deprecated, however it is immediately LC'ed to steeringForceFactor. As there is no change in functionality when steeringForceIgnoresSpeed is false, this has no effect on any packs to my knowledge. Demonstrational Video

https://github.com/DonBruce64/MinecraftTransportSimulator/assets/53581325/dfe40d9d-b263-4e3a-b672-5b83441816fc

*sigh* Point, not ponit.

DonBruce64 / MinecraftTransportSimulator