Add no_std support to orbita3d_kinematics crate

[omelia-iliffe]

Thanks for your help resolving #92. As mentioned here is a PR with the work I have done to make orbita3d_kinematics no_std compatible.

I have made a number of changes:

• add an optional std feature (could be default)
• use core instead of std where possible for const PI, TAU, etc
• remove ndarray_einsum_beta dependency opting instead to do the calculation manually forward.rs:261
• remove unused ndarray and nshare dependencies
• use nalgebra::{ComplexField, RealField}; for methods such as sin, atan2, etc
• add GammasOutOfRange error instead of returning a Box<dyn std::error:Error> inverse.rs:145
• refactored compute_valid_solution to remove need for Vec inverse.rs:201
• add a rem_euclid function

I did some simple bench-marking to ensure I wasn't significantly impacting performance. There was improvements in inverse kinematics (-9%) and significant improvements in forward kinematics (-69%). Bench code here