robust invese kinematics

[askuric]

Ok, this PR adds the inverse kinematics solution that automatically modulates the body yaw to improve the robustness.
The PR only uses the reachy_mini_rust_kinematics function that does this under the hood. Just an API call:
See: pollen-robotics/reachy_mini_rust_kinematics#3

What it does?
It modulates the body yaw:

1. to limit it between certain hard limits in hardware (eg.+-160 deg)
2. to limit the relative yaw between the platform and the body (eg. 65 deg in placo) - this improves the robustness a lot allowing to avoid singularities

IMPORTANT this new ik function inverse_kinematics_safe returns 7 joints (body_yaw + 6 Stewart platform motors) while the inverse_kinematics returned only the 6 Stewart platform motors.

To test it use the feat_robust_symbolic_ik branch of reachy_mini and reachy_mini_rust_kinematics.