Pulled the gui out into VkGUI to separate it out.

vk_gui.h

@@ -0,0 +1,18 @@
+#pragma once
+#include "vk_types.h"
+
+class VulkanEngine;
+
+class VkGUI {
+  public:
+  bool should_quit = false;
+  bool stop_rendering = false;
+
+  struct SDL_Window* init_window(VkExtent2D windowExtent);
+  void init_imgui(VulkanEngine& engine);
+  void draw_imgui(VkExtent2D& swapchainExtent, VkCommandBuffer cmd, VkImageView targetImageView);
+  void render_imgui(std::vector<ComputeEffect>& backgroundEffects, int* currentBackgroundEffect);
+  void destroy(struct SDL_Window* _window);
+
+  void poll_event();
+};