Resolve "(viz): negato_3d does not respect initial or restore visibility setting"

Description

This solves minor visibility issues with the negato_3d adaptor.

How to test it?

First issue

• Modify tuto07_generic_scene/plugin.xml to add visible="false" inside the <config> tag of the negatoAdp service
• Launch tuto07_generic_scene
• Open an image
• Observe the image is not displayed with the negato

Second issue

• Modify tuto07_generic_scene/plugin.xml with this patch
• Launch tuto07_generic_scene
• Open an image
• Observe the image is displayed
• Click on the snapshot button
• Observe the image is hidden
• Open an image again
• Observe the image is not displayed with the negato

Related issue(s)

Closes #1247 (closed)