Improvements to BezierCurve, BezierSurface, NURBSCurve and NURBSPatch interfaces

[kennyweiss]

While using the NURBSCurve class, I noticed several usability enhancements:

• Simplify the constructors -- there are numerous constructors for these classes, taking arrays of control points, weights and knot spans. Each has overloads for axom::Array and c-style arrays (+extra size parameters). We should simplify this to take array-like template parameters for classes that have a size() function and a subscript operator. This should then work for std::vector, axom::Arrayandaxom::ArrayView`. It will be straightforward for users to wrap their c-style arrays in an axom::Array.
• Provide references to control points, weights and knot spans. Without these, it can be awkward to copy/manipulate the curves and surfaces