Update trajectory-generator and move base trajectories out of sot-torque-control to separate package

[proyan]

• Adds playSpline to load splines from a file
• Adds required dependency to stack-of-tasks/parametric-curves package
• Moves nd-TrajectoryGenerator base trajectories out of sot-torque-control to parametric-curves
• Everything except Text-File Trajectory Generator tested on simulation. TODO: Currently, it disables constant-acceleration and triangle-trajectory (still to be impemented in parametric-curves)

[proyan]

• constant-acceleration trajectory tested and activated in last commit