refactor: create gui widget classes

include/render/gui/TowerPlacePopup.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "GuiWidget.h"
+
+#include <glm/glm.hpp>
+
+namespace td {
+namespace gui {
+
+class TowerPlacePopup : public GuiWidget {
+private:
+    glm::vec2 m_ClickWorldPos;
+public:
+    TowerPlacePopup(client::Client* client);
+
+    virtual void render();
+
+    void setClickPos(const glm::vec2& worldPos);
+};
+
+} // namespace gui
+} // namespace td