Resolve "Implement image flip service"

What does this MR do?

• Add a SFlip filter to flip images in the 3 directions

How to test it?

• Build Tuto06Filter with this MR
• Launch the tests and ensure that the imageFilterOpTest runs OK
• Launch the Tuto06Filter app
  • Load an image
  • In the Filter menu, press on Toggle vertical image flipping and ensure that your input image is flipped in the right view

Some results

The image should be flipped vertically.

Associated Issues/Merge Requests

Closes #201 (closed)