Axisymmetric geometries

[totork]

Less of an issue but more of a QoL point.

Right now, even for axisymmetric geometries like Tokamaks, we do the tracing for all cross sections. This should be able to be reduced to just doing it once for one cross section and then copying the results to remaining positions.

This would be my approach of a first test, instead of iterating through all ny, at the end of the first if the bool axisymmetric==True, copying this to all other cross sections and then leaving the loop?

[dschwoerer]

It might be easier to write a wrapper that creates the grid for only one point in y, and than copies that, then changing it everywhere in the code.