* refactor: More intuitive positioning of parabolic mirrors + bug fix for oap telescopes

* Added parabolic mirror tests

* added anchor point isometry to surface for parabola and added effective_surface_isometry method

* refactor name of method

* cargo fmt

* added tests for parabolic mirror

* cargo xtask ci

* absolute value for angle check

* extra cehck for off-axis angle

* oaps are now defined via their effective off-axis focal length and the off axis angle

* changed input of parabolic mirror to use the effective focal length