New organization and bidings to call Gait, FootstepPlanner and FootTrajectoryGenerator directly from Python

* Code cleaning and refactor
* Add Types, FootTrajectoryGenerator, Gait, FootstepPlanner classes
* Rename quadruped-reactive-walking qrw

Authored-by: Fanny Risbourg <frisbourg@laas.fr>

Reswitch to old estimator values + Put back things that should not have been cleaned + Try fixing gepetto viewer

Add contact force limitation when a contact is activated to avoid directly applying a huge force (ramp shape for the limit)

Finish OSQP implementation (not working because needs symmetric P matrix) + Add dependency to eiquadprog