Change 'nr_cones_big_angle' and 'nr_cones_small_angles' to 'angles_discretization'

For homogeneous systems, instead of having nr_cones_big_angle (int) and nr_cones_small_angles (list of int) as distinct parameters, we can have a single parameter called angles_discretization, which is list of int and its first entry corresponds to nr_cones_big_angle and the rest entries make up the nr_cones_small_angles. For example, if u had nr_cones_big_angle=6 and nr_cones_small_angles=[4,5], we should now have angles_discretization=[6,4,5]. This suffices to be changed only on the parser side, i.e. the user side (because the current thing would be confusing for a user).

Also, the code should throw an error if the length of angles_discretization is not equal to dim-1, where dim is the dimension of the system (of the original system, without the sampling error in the dynamics).