(visuOgreQt): send mouse modifiers as keyboard events

What does this MR do?

• Take mouse modifiers into account for mouse events.
• This is a quick fix and should be refactored later on.

How to test it?

• Run OgreViewer
• Load a VTK mesh (Ctrl+M)
• Don't click inside the render window.
• Ctrl+left on the mesh
• A point should be picked.

Related issues/MR

• Merge requests
  • depends on !277 (merged)