Vectorized Raycasts

[wahln]

This (draft) PR vectorizes the raycast-operations within the siddon ray-tracer so multiple rays can be casted at once and sets up a OO system for implementing RayTracers. The method handles the problem of having a different number of plane crossings by padding the corresponding matrices for the respective quantities with NaNs. It is substantially faster (in Matlab as well as Octave) than the current for loop and downwards compatible (the old functions still exist but use instances of the class now).

The current PR is marked as draft because I want to implement some further streamlining, but I wanted to open the code for comments.

[github-actions[bot]]

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