0033551: Visualization - Add new transform persistence mode to force orthographic...

0033551: Visualization - Add new transform persistence mode to force orthographic projection on object.

The new transform persistence mode, with flag `Graphic3d_TMF_OrthoPers`, can be combined (bitwise OR operation) with the other persistence modes (2D, Trihedron or Zoom/Rotate Persistence) to make objects be rendered with orthographic projection when it is on a view with perspective projection.

If the view already uses orthographic projection, there will be no difference.

This feature was implemented to fix ViewCube being distorted when view with perspective projection changes size.