Introduction of PolyX fit function to CalculateTransmission

re #7734
Re #7734. Resolve overload ambiguity on the Mac.
Change the CalculateTransmission parameter

Instead of having the FitMethod with PolyX, change it to Polinomial and
add a new parameter PolynomialOrder to set up the order.

It may solve the building tests problem in mac os

re #7734
Fix CalculateTransmission in mac os

Adding Levenberg-MarquardtMD minimizer to polynomial fit solves the issue
of breaking the unit test inside mac os - snow leopard.

re #7734
Merge remote-tracking branch 'origin/feature/7734_polyn_trans_fit'