Add render graph proof of concept and refactor graphics

Implemented a transient render graph system as a proof of concept, including resource aliasing, pass culling, and typed pass data. Added new project `Ghost.RenderGraph.Concept` targeting `.NET 10.0`.

Refactored graphics-related components:
- Simplified resource state transitions in `RenderingContext`.
- Improved resize handling in `GraphicsTestWindow`.
- Updated `D3D12GraphicsEngine` to streamline frame rendering.
- Enhanced `D3D12ResourceDatabase` and `D3D12SwapChain` for better resource management.

Added detailed documentation:
- `ALIASING.md` explains resource aliasing techniques.
- `API_DESIGN.md` outlines the render graph API design.

Updated solution to include the new render graph project.

Ghost.RenderGraph.Concept/RenderGraphBlackboard.cs

@@ -0,0 +1,36 @@
+namespace Ghost.RenderGraph.Concept;
+
+public class RenderGraphBlackboard
+{
+    private readonly Dictionary<Type, object> _data = new();
+
+    public void Add<T>(T data) where T : class
+    {
+        _data[typeof(T)] = data;
+    }
+
+    public T Get<T>() where T : class
+    {
+        if (_data.TryGetValue(typeof(T), out var data))
+        {
+            return (T)data;
+        }
+        throw new KeyNotFoundException($"Data of type {typeof(T).Name} not found in blackboard.");
+    }
+
+    public bool TryGet<T>(out T? data) where T : class
+    {
+        if (_data.TryGetValue(typeof(T), out var obj))
+        {
+            data = (T)obj;
+            return true;
+        }
+        data = null;
+        return false;
+    }
+
+    public void Clear()
+    {
+        _data.Clear();
+    }
+}