Update Screen system

Added FuelScreen (Working buttons)
Added SellScreen (Nothing working)

Game/GameManager.h

@@ -0,0 +1,12 @@
+#pragma once
+#include "Player.h"
+
+class GameManager
+{
+public:
+	float balance{ 0.0f };
+	float fuel{ 0.0f };
+
+private:
+	GameManager() = default;
+};