(fwRenderOgre): allow pickers to pick both side of meshes

What does this MR do?

Take into account the culling mode of entities for the picking. It allows to know which sides of the triangle to pick.

How to test it?

• Launch OgreViewer
• Open any mesh
• Try to add landmarks with CTRL+Click

Try multiple meshes to ensure that the picking method are not broken.

Associated Issues/Merge Requests

• Issues
  • See #373 (closed)