Reorganise some folders
What does this MR do?
After the big merge with fw4spl-ar, fw4spl-ogre and fw4spl-ext, it was necessary to clean up a bit the folders hierarchy, notably to group related items together. No project is renamed, the projects were only moved or their parent directory was renamed.
How to test it?
- check new locations and new names look good,
- build everything.