Adding parametric coordinates to MeshField Shapes

[hgangwar]

This PR proposes a way to embed parametric coordinates directly in MeshField shape structs. This will:

• allow Omega_h_layout to compute DOF coordinates for higher order shape functions.
• extend Omega_h_layout implementation to 3D use cases. See Omega_h_layout.cpp.

[hgangwar]

@jacobmerson

[cwsmith]

Thank you @hgangwar . Assuming this is for node parametric coords, we have a working branch that addresses this (look for getNodeParametricCoords) https://github.com/SCOREC/meshFields/blob/cws/ordering/src/MeshField_Shape.hpp .
Note, as hinted at in the branch name, there are ordering issues that are being worked on. I hope to get back to this mid next week and get this merged by Feb 3rd or so.