Add profile-based thrust propulsion model
The new architecture for maneuvers, separating triggers from thrust was introduced almost three years ago with version 10.2. Orekit only provides constant thrust models (one basic and one with scale factors) and users have to implement their own thrust models if they want time-dependent behavior. It would however be relevant to have a general model with piecewise polynomials in thrust and constant Isp. One trick is that the switch from one polynomial to the next one should be located accurately as it introduces discontinuities in the force model.