Rework the GUI so it uses SFMLBackend by moving the SoundQuip into SFMLBackend.

gui.hpp

@@ -1,29 +1,13 @@
 #pragma once
 
-#include <efsw/efsw.hpp>
-#include "game_engine.hpp"
-#include <filesystem>
 #include <string>
-#include <SFML/Audio.hpp>
-#include <nlohmann/json.hpp>
+#include "game_engine.hpp"
+#include "sfmlbackend.hpp"
 
 using std::string;
 
 class Builder;
 
-class SoundQuip {
-public:
-  sf::Sound sound;
-  sf::SoundBuffer buffer;
-  bool initialized;
-
-  SoundQuip() {};
-
-  void load(nlohmann::json &data, const char *in_file);
-  void play();
-  void stop();
-};
-
 class GUI {
   std::vector<string> _lines;