Evaluate use of Plane markup

[jcfr]

To define a planes, the user is currently expected to:

• click on "Compute around bounding box"
• select the model for projection
• create a "connected landmark list"
• click "add a new plane"
• manually place 3 fiducials and make sure the correct fiducials are associated with the plane

To streamline this process and rely on the new plane markups, here are few questions:

• what is the role of the "Define middle point between two landmarks" ? Is this is still needed ?
• the save/load plane is an undocumented format specific to this extension. Are these files used ? Can we now use the new "json" format used to save markup annotation in Slicer ? (it is versioned and has a schema)

The plane markup is also associated with 3 fiducials and provide a mechanism to easily adjust angle/origin of the plane by showing an interactive tool:

By using the plane annotation, we would remove a lot of code in the extension and would simply display a list of plane markup annotations.

cc: @msyatabe

[bpaniagua]

Bravo, JC!
cc: @luciacev

[jcfr]

what is the role of the "Define middle point between two landmarks" ? Is this is still needed ?

Look like we could remove the middle point functionality from this extension as it is already part of https://github.com/DCBIA-OrthoLab/Q3DCExtension ?