New node located at the wrong place

[AxelRICHARD]

1. Create Package Package1
2. Create Package Package2 in Package1
3. Create PartDefinition PartDefinition1 in Package2
4. Create PortUsage port1 in PartDefinition1.

Expected result:
port1 should appear as a border node of PartDefinition1.

Actual result:
port1 appears as a border node of PartDefinition1
port1 also appears as a sibling node of Package1 with a composition edge to PartDefinition1. This node should be hidden by default AND it should be located inside Package2, not inside Package1.