Drag and drop multiple deployment links

[GlennPlou]

PR: #2885

When drag and dropping a deployment link (with multiple deployment links enabled), other links are removed.

For example, if I drop PC4 from PC2 to PC3, PC4 in PC1 is removed and should not.

Steps to reproduce:

Initialization

• Create a new PAB diagram, add 3 Physical Components with "Node PC" tool and another one with "Deploy Behavior PC".
  
• In Window > Preferences > Capella > Model, check "Multiple deployment allowed"
  
• Add a deployment for "PC 4" in "PC 1" with "Manage Behavior PCs Deployment" tool in palette.
  
  
• In Filters and Customization of the Capella Project Explorer, uncheck "Parts" filter to reveal "[Part Deployment Link]" in the Project Explorer
  
  

Scenario

• Drag and Drop PC 4 from PC 2 to PC 3.
  Expected: PC 4 is removed from PC 2, added to PC 3, and PC 1 remain unchanged.
  Actual: K-O --> All previous references of PC 4 have been removed (Deploying Parts in Properties view > Semantic tab), and two have been added in PC 3 (Deployment Links in Properties view > Semantic tab)
  
  
• Undo. Drag and drop PC 4 from PC 2 to PC 1.
  Expected: DnD is not allowed since PC 2 is already deployed in PC 1.
  Actual: K-O --> Drag and drop is made. PC 2 has no longer PC 4 Deployment Link, and PC 1 has two Deployment Links