[Sirius][Integration] Several commands are executed for each creation in a Sirius Diagram

The Papyrus Command Stack view can be used to identify the Problem.

Steps to reproduce:

1. Create a new Papyrus-Sirius class Diagram
2. Save
   1. Create a new Class -> 2 commands are executed into the CommandStack
   2. Create another Class -> still 2 commands are executed into the CommandStack
3. The user need to do 4 undo to cancel 2 classes creations