(visuOgreAdaptor): new adaptor to output renderTarget as an Image

What does this MR do?

Add a new adaptor SFragmentsInfo that takes informations of the configured layer like, informations can be color, depth or primitive ID.

Some minors updates are also pushed in this MR:

1. SMaterial can now be configured with a representatioMode (SURFACE/POINT/EDGE/WIREFRAME).
2. Add new conversion function in fwRenderOgre::helper::Camera to convert from screen space to NDC or viewspace. deprecates the old ones.

How to test it?

1. Compile OgreViewer
2. Run It !
3. Load a Mesh/Image in the Ogre Scene.
4. Click on the last button at the right of the toolbar to save your snapshot. (Save it in Bitmap ( use the .png ) format).

Data

No data required

Some results

Here's a non available sample of the use of SSnapshot:

Snapshot image is displayed in a imshow window:

Associated Issues/Merge Requests

Closes #451 (closed)