0027358: ShapeAnalysis_Curve::GetSamplePoints iteration logic isn't robust

0027358: ShapeAnalysis_Curve::GetSamplePoints iteration logic isn't robust

The iterating logic in ShapeAnalysis_Curve::GetSamplePoints() is made more robust: instead of iterative incrementing parameter by adding step, parameter at each point is calculated independently from index.
This avoids possible accumulation of numeric errors, and ensures that generated points are equally spaced and their quantity is respected in all cases.