Refactor GPU resource management and rendering pipeline

- Introduced `Handle<T>` and `Identifier<T>` for lightweight, strongly-typed resource identifiers.
- Replaced `BitSet` with `UnsafeBitSet` for improved performance and memory safety.
- Refactored `Mesh` and `Material` into `MeshClass` and `MaterialClass` for better GPU resource handling.
- Added `D3D12ResourceDatabase` to centralize GPU resource tracking and lifecycle management.
- Updated `D3D12ShaderCompiler` to load shaders from disk and dynamically populate constant buffers and textures.
- Enhanced `ICommandBuffer` with new upload operations for buffers and textures.
- Refactored `Vertex` struct for simplified memory layout and better performance.
- Updated `MeshBuilder` and rendering logic to align with new resource and shader structures.
- Added `BindlessDescriptor` support to `TextureHandle` and `BufferHandle`.
- Removed unused classes and performed general cleanup.
- Updated unit tests and demos to reflect the new architecture.

Ghost.Graphics/RHI/IResourceDatabase.cs

@@ -1,4 +1,5 @@
-using Ghost.Graphics.Data;
+using Ghost.Core;
+using Ghost.Graphics.Data;
 
 namespace Ghost.Graphics.RHI;
 
@@ -32,4 +33,24 @@ public interface IResourceDatabase
     /// </summary>
     /// <param name="handle">The handle of the resource to be removed.</param>
     public void RemoveResource(ResourceHandle handle);
+
+    public Identifier<Mesh> AddMesh(ref readonly Mesh mesh);
+
+    public bool HasMesh(Identifier<Mesh> id);
+
+    public Mesh GetMesh(Identifier<Mesh> id);
+
+    public ref Mesh GetMeshReference(Identifier<Mesh> id);
+
+    public void RemoveMesh(Identifier<Mesh> id);
+
+    public Identifier<Shader> AddShader(ref readonly Shader shader);
+
+    public bool HasShader(Identifier<Shader> id);
+
+    public Shader GetShader(Identifier<Shader> id);
+
+    public ref Shader GetShaderReference(Identifier<Shader> id);
+
+    public void RemoveShader(Identifier<Shader> id);
 }