Enhance support for symmetries in potential calculation

Right the user is able to define the world in the config file.
Symmetries can be used there. For example mirror symmetries.

The issue is that the symmetries might differ for different things to simulate.
For example, the example coax detector has in general a periodicity of 60° in φ.
In addition, within this period, it has a mirror symmetry.
Thus, the electric potential only needs to be calculated on the interval [0°, 30°] (with reflecting boundary conditions in φ).

However, this is not possible for the weighting potentials of individual segments. Those, in this case, have
only a mirror symmetry but not a periodicity. Thus, they are calculated over 360°.
It could be reduced to [x°, x°+180°].

For this we need to add support for defining those symmetries in the configuration files for each individual contact.