(visuOgreAdaptor): set the origin of the SNegato2D to a corner

What does this MR do?

This MR move the origin of the ::visuOgreAdaptor::SNegato2D on the lower left corner. This change is necessary because the distance system (which is currently running on vtk) returns values from the lower left corner of the image. To work with Ogre, we need to change the current origin that in the middle of the image.

It also modifies the method used to change the orientation of the negato.

How to test it?

Launch OgreViewer, load an image, the negato display should be the same as before.

Associated Issues/Merge Requests

• Issues

  • Closes #247 (closed)
  • See #163 (closed)

• Merge requests

  • !100 (merged)