Add first_intersection / first_intersected_primitive to CGAL_AABB_tree bindings

[noamgat]

Just like any_intersection() / any_intersected_primitive() have been added to the swig binding for CGAL_AABB_tree, it would be very helpful if first_intersection / first_intersected_primitive() would be added as well (even without the skip functor), as they are the most important data when raycasting. It should be easy, given that the any variant is there.

If that is impossible, perhaps updating the python example AABB_triangle_3_example.py for using "all_intersected_primitives"? it expects a "Primitive iterator helper" which I have no idea how to construct in python.

Thanks!

[noamgat]

Created a PR: https://github.com/CGAL/cgal-swig-bindings/pull/187