MPhys wrapper: Standardize and cleanup the pygeo wrapper

[anilyil]

Description of feature

the pygeo wrapper can be cleaned up substantially and we can also make the integration with the new api smoother.

In particular, during reverse mode derivative computations, it does unnecessary work when we have many thickness constraints, but pygeo still evaluates the full jacobian including the cfd surface nodes even though their seeds are zero.

Moved the issue from the mphys repo: OpenMDAO/mphys#62

Potential solution