Add nose cone drag effect.

Increases drag on things in a stack that do not have a filled stack node. This means nose cones with only one stack node, will have less drag. The flip side of this is that engines will have more drag, as they have a missing node (where the fire comes out), Meaning this should also help stabilize vessels, as the engines will want to face backwards (as they have more drag).
This here... so we don't have to call it in fixed update later, and you never change the value.