Graphics: Rework RenderTargets

- RenderTarget have been moved to the Graphics module and are now lightweight objects between the target of rendering (swapchain or texture)
- RenderTexture no longer require a blit between the framegraph texture and the target texture (the target texture is now directly rendered onto using a new feature of the framegraph)
- ForwardFramePipeline viewers are now properly ordered by render order

include/Nazara/Graphics/RenderWindow.inl

@@ -0,0 +1,16 @@
+// Copyright (C) 2023 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Graphics module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Graphics/Debug.hpp>
+
+namespace Nz
+{
+	inline RenderWindow::RenderWindow(Swapchain& swapchain) :
+	m_swapchain(&swapchain),
+	m_windowSwapchain(nullptr)
+	{
+	}
+}
+
+#include <Nazara/Graphics/DebugOff.hpp>