Flexgrid in the topology

Adapt the topology management to handle flex grid and pass from used/avalaible wavelength model to the Binary model that describes spectrum occupation. This also implies some adaptations in other modules that contribute in populating/changing the topology such as the renderer. Implies to move to R7.1 of Network Model.

Evaluation indicators: code pushed on the branch that best fit and minimize the workload, not necessarily merged, build + Junit OK, functests passed