(SImageMultiDistance): improve interactions and resources management

What does this MR do?

• Fixe ::visuOgreadaptor::SImageMultiDistance.
• Add auto-snap on distances.
• Update distance on multiple scene.
• Improve resources management.
• Use our new interactor API.

How to test it?

• Open OgreViewer.
• Load any image.
• Go to the negato view.
• Add distances and interact with them.

Some results

You can event use the 2D negato and distances in a 3D scene.

Associated Issues/Merge Requests

• Issues

  • Fixes #437 (closed)
  • See https://git.ircad.fr/Sight/sight/issues/108

• Merge requests

  • Depends on https://git.ircad.fr/Sight/sight/merge_requests/307
  • Depends on https://git.ircad.fr/Sight/sight/merge_requests/319