feat(lua): much more complete imgui bindings, allow lua imgui callbacks from outside yimmenu classic tabs through gui.add_imgui(func) but also inside yimmenu classic tabs through tab:add_imgui(func) (#1736)

src/lua/bindings/gui/raw_imgui_callback.cpp

@@ -0,0 +1,15 @@
+#include "raw_imgui_callback.hpp"
+
+namespace lua::gui
+{
+	raw_imgui_callback::raw_imgui_callback(sol::protected_function callback) :
+		m_callback(callback)
+	{
+
+	}
+
+	void raw_imgui_callback::draw()
+	{
+		m_callback();
+	}
+}

src/lua/bindings/gui/raw_imgui_callback.hpp

@@ -0,0 +1,20 @@
+#pragma once
+#include "gui_element.hpp"
+#include "lua/sol.hpp"
+
+namespace lua::gui
+{
+	// Lua API: Class
+	// Name: raw_imgui_callback
+	// Inherit: gui_element
+	// Class for representing a raw imgui callback.
+	class raw_imgui_callback : public gui_element
+	{
+		sol::protected_function m_callback;
+
+	public:
+		raw_imgui_callback(sol::protected_function callback);
+
+		void draw() override;
+	};
+}