Add sensor sensitivity field calculation

[faberno]

Please describe your 🚀 feature request.
To potentially improve the reconstruction quality, we could simulate the sensitivity field of the sensor elements and use it for weighting during the reconstruction.

Additional context
Sensitivity Field Simulation Algorithm:

1. Sample Points on transducer surface
2. For each voxel:
   2.1) Create a histogram of the distances to all transducer-subelements
   2.2) Convolve histogram with a photoacoustic model-signal (N-shape)
   2.3) The sensitivity value of the voxel is the difference between max and min of the convolved signal