Update to the transfom-saving approach to virtual fitting.

[ebrahimebrahim]

Update SlicerOpenLIFU virtual fitting to work with the design introduced in OpenwaterHealth/OpenLIFU-python#179

This means

• After a virtual fit is complete, a new transform node is created representing the virtual fitted transducer transform. This happens regardless of whether there's an active session. It should be tagged with an attribute indicating which transducer ID it was meant for.
• Even though a new transform node was created, the transform node that is applied to the transducer model is still the "current transducer transform" that we already have. And this is still updated. So no change here.
• If there is an active session when running virtual fitting, then the virtual fit result (including the transform) is additionally written into the active session
• The session status view should be updated to show virtual fit related status
• The preplanning module should show virtual fit status as well

Yet to clarify: How should the new transform node be handled? Is it an "openlifu object" to be listed in the list of openlifu objects? Or is it an affiliated object of other things (like how the "current transducer transform node" is affiliated to the SlicerOpenLIFUTransducer)? What happens when you load a session that has virtual fitting info -- does it load the transform?

Depends on OpenwaterHealth/OpenLIFU-python#179
Depends on #139

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Traceability Information:

• Issue: SlicerOpenLIFU#145
• SOFTREQ: SlicerOpenLIFU#33
• Comment: This issue is related to the requirements defined in SlicerOpenLIFU#33.

This information was populated automatically by a script on 2025-06-09T18:03:58Z.