Adapt PCE & functional test considering OMS absence

Adapt PCE & functionnal tests to take into account the needed presence of OMS. Now that OSNR is calculated, a path can not be considered as eligible in the absence of OMS on the ROADM to ROADM links, because OMS attributes are needed either to calculate OSNR or to calculate target output power depending on the loss of following ROADM-ROADM link. Thus the absence of valid OMS attributes shall trig an error and path refusal. Functionnal test need to be adapted considering that OMS attributes shall be present.