Radium dataflow rendering

[MathiasPaulin]

Pull Request Description

This PR is a draft for Node base rendering in Radium.
It extends the PR #1007 with dedicated nodes for rendering and a new type of renderer.
This PR will be rebased (and then force pushed) on any changes in PR #1007
Note that this PR only adds 17 files to the PR #1007 (whose number of files should decrease by removing examples duplicated in unittests)

This PR is stills draft as under heavy work (porting from prototype to the PR)

Right now, the system is quite fonctionning with only a few rendering nodes available

TODO

• Add more rendering nodes
• Add compositing nodes
• Add image processing nodes
• Allow renderers to execute several graphs ( e.g. one per Ro types ) before compositing their results
• Simplify and review code
• Docs, tests, ...

[codecov]

Codecov Report

Merging #1018 (ab4b5da) into release-candidate (fe7d934) will increase coverage by 1.15%.
The diff coverage is 53.31%.

❗ Current head ab4b5da differs from pull request most recent head 66c36f9. Consider uploading reports for the commit 66c36f9 to get more accurate results

@@                  Coverage Diff                  @@
##           release-candidate    #1018      +/-   ##
=====================================================
+ Coverage              45.65%   46.81%   +1.15%     
=====================================================
  Files                    312      390      +78     
  Lines                  23060    27333    +4273     
=====================================================
+ Hits                   10529    12797    +2268     
- Misses                 12531    14536    +2005     

Impacted Files	Coverage Δ
src/Dataflow/Core/Enumerator.hpp	0.00% <0.00%> (ø)
...ataflow/QtGui/GraphEditor/ConnectionStatusData.hpp	0.00% <0.00%> (ø)
src/Dataflow/QtGui/GraphEditor/GraphEditorView.cpp	0.00% <0.00%> (ø)
...c/Dataflow/QtGui/GraphEditor/GraphEditorWindow.cpp	0.00% <0.00%> (ø)
...c/Dataflow/QtGui/GraphEditor/GraphEditorWindow.hpp	0.00% <0.00%> (ø)
...rc/Dataflow/QtGui/GraphEditor/NodeAdapterModel.cpp	0.00% <0.00%> (ø)
...rc/Dataflow/QtGui/GraphEditor/NodeAdapterModel.hpp	0.00% <0.00%> (ø)
src/Dataflow/QtGui/GraphEditor/WidgetFactory.cpp	0.00% <0.00%> (ø)
src/Dataflow/QtGui/GraphEditor/WidgetFactory.hpp	0.00% <0.00%> (ø)
...Dataflow/Rendering/Nodes/AntiAliasing/FxaaNode.cpp	0.00% <0.00%> (ø)
... and 74 more

... and 2 files with indirect coverage changes