No mesh visualization from ttool when the pose is validated

[9and3]

As now (see image), when the toolhead is validated a blue mesh is present.
Although this can help to see if the object locking is still valid over time it presents a heavy widget on the UI.

Let's try to disable automaticaly the visualization as the tool pose is validated (saved).
There is already a button that does that in the UI pannel (Toolhead > DrawSilhouette thickbox).

--> Another option is to have only the green contours and not the blue mesh. Maybe it's possible to assign a color with alpha=0 to be transparent.