Update curve dependency

[nim65s]

Hi,

This package still depends on the old parametric-curves library:

sot-talos-balance/CMakeLists.txt

Line 58 in 8749650

ADD_REQUIRED_DEPENDENCY("parametric-curves")

This should be updated to https://github.com/loco-3d/curves

[pFernbach]

Hi, unfortunately Curves do not have all the features required for an easy refactoring of sot-balance-balance yet. See https://gepgitlab.laas.fr/loco-3d/curves/issues?milestone_title=sot-talos-balance+requirements

Most of this issues seems quite easy to solve, but there is some discussion on the design and expected behavior that never converged. I will probably take care of the "easy" issues, but not before several weeks.

[olivier-stasse]

@nim65s Everything depends on one object called nd-trajectory-generator.cpp.
We had a request from @andreadelprete to move this object to sot-core as it used by sot-torque-control.
stack-of-tasks/sot-torque-control#70
From a practical viewpoint I do not see why we could not switch in this repo to the new library.
For now this is not a blocking issue, but indeed we should get rid of parametric-curves.