Rework Project Ultra

- Added container
- Made container the base of Layout
- Set Containers theirself as pParent for Elements on Push

include/pd/ultra/layout.hpp

@@ -1,28 +1,23 @@
 #pragma once
 
 #include <pd/ultra/canvas.hpp>
+#include <pd/ultra/container.hpp>
 #include <pd/ultra/elems/element.hpp>
 
 namespace PD {
 namespace Ultra {
-class PD_API Layout {
+class PD_API Layout : public Container {
  public:
   Layout() {}
   ~Layout() {}
 
-  void Add(ElementBase& elem);
-
   void SetFont(PD::Li::Font& font);
 
   void Render();
 
   const PD::Li::Drawlist& Data() const { return pList; }
-  Canvas& GetCanvas() { return pCanvas; }
-  const Canvas& GetCanvas() const { return pCanvas; }
 
  private:
-  Canvas pCanvas;
-  PD::Pool<ElementBase*> pElements;
   PD::Li::Drawlist pList;
 };
 }  // namespace Ultra