PCE func tests to consider oms-attributes absence

- Compute a path in complex_topo_uni_dir_data from Xponder2-2 to Xponder-1-2
- Check that the path goes through the link
OpenRoadm-1-3-DEG2-to-OpenRoadm-1-2-DEG2
- Delete the oms-attributes of OpenRoadm-1-3-DEG2-to-OpenRoadm-1-2-DEG2
- Compute a new path between the same source/destination nodes as the first
- Check that the new path does not go through the link
OpenRoadm-1-3-DEG2-to-OpenRoadm-1-2-DEG2

JIRA: TRNSPRTPCE-69
Change-Id: Icc6fe79fc0bc4f0cc47c6230f461894576529744
Signed-off-by: atriki <ahmed.triki.tn@gmail.com>