Additional bend point added when setting model second time

[glatuske]

When setting the same model twice, the second time all edges get an additional bendpoint (actually the 0,0 of the block the source port is attached to).

[glatuske]

@gfontorbe @spoenemann

I have checked the backend code. Sprotty diagram server sends for the models the RequestBoundsAction

On the client side that leads to SetModelCommand for the first and UpdateModelCommand for the second.

I hope that helps you to replicate it.

[glatuske]

For the moment I have fixed it by generating unique IDs across graphs/diagrams.