Expand scripts.tmtemod

[prisae]

At the moment, scripts.tmtemod only works for ab=11. Expand it to work for all electric sources and receiver (and maybe even for rotated sources and receivers).

For electric sources and receivers it should be straight forward. Expanding it to magnetic sources and receivers is also possible, but it is not a task of pure programming, as it involves some maths beforehand to calculate the required non-physical contributions.

https://empymod.readthedocs.io/en/stable/addons.html#tmtemod-calculate-up-and-down-going-tm-and-te-modes