add imgui support

include/client/ImGuiAppComponent.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <Nazara/Core/ApplicationComponent.hpp>
+
+namespace Nz {
+
+class Window;
+class Texture;
+
+}  // namespace Nz
+
+namespace blitz {
+namespace client {
+
+class StateData;
+
+class ImGuiAppComponent : public Nz::ApplicationComponent {
+  public:
+	ImGuiAppComponent(Nz::ApplicationBase& app, Nz::Window& a_Window);
+	~ImGuiAppComponent();
+
+	void Update(Nz::Time elapsedTime) override;
+
+  private:
+	Nz::Window& m_Window;
+	std::shared_ptr<Nz::Texture> m_FontTexture;
+
+	void SetStyle();
+	void UpdateFontTexture();
+};
+
+}  // namespace client
+}  // namespace blitz