UE::CADKernel::ComputeSlopeRelativeToNearestAxis

Return a slope between [0, 1] relative to the nearest axis between horizontal or vertical axis i.e. ComputeUnorientedSlope => 0.5 return 0.5 ComputeUnorientedSlope => 2.3 return 0.3 ComputeUnorientedSlope => 3.6 return 0.4