(visuOgreAdaptor): take landmarks visibility into account

What does this MR do?

It allows ::visuOgreAdaptor::SLandmarks to take the landmarks visibility into account.

Data

landmarks.json

How to test it?

• Launch OgreViewer
• File -> Open landmarks
• Choose landmarks.json
• Press R to reset the camera.
• Group 4 must not be displayed with this MR.

Associated Issues/Merge Requests

• Issues
  • Closes #330 (closed)