Signed Distance for PlasmaVesselDistance

[dpanici]

trafficstars

Adding a sign to the distance calculated could ensure that situations where the plasma surface might be outside the vessel cause the objective to push the plasma back inside the vessel. This could be done by e.g. evaluating the distance from the magnetic axis to the plasma surf and the vessel surf, and using the sign of r_vessel - r_plas where if the sign is negative, the plasma is actually outside the vessel surface

[dpanici]

maybe an option could be added to the objective like signed=True where if given, augments the objective with another cost that is zero when sign(r_vessel-r_plas)>0 (i.e., vessel is outside of plasma) and is positive and large when the opposite is true

[dpanici]

will be resolved by #817

[dpanici]

Resolved by #817