OMS attribute feeling

In the topology management, during link discovery, call OLM to calculate the span-loss,and fill OMS attribute in the topology. Because we calculate now OSNR, we need to fill in the topology span-loss current and base (at first time). Need to define the procedure on how to update the OMS attribute in the topology first. In a second step, identify if specific code needs to be develop to handle it in a scalable way.
_Complement input topology file used for test with OMS information
_Check consistency of span-loss base/current rpc handling
_Check consistency of PCE and OLM code according to this and make needed changes
_Make needed adaptations