feat: go back in menu on Escape pressed

src/engine/Engine.cpp

@@ -26,6 +26,7 @@
 #include "graphics/core/ImageData.hpp"
 #include "graphics/core/Shader.hpp"
 #include "graphics/ui/GUI.hpp"
+#include "graphics/ui/elements/Menu.hpp"
 #include "objects/rigging.hpp"
 #include "logic/EngineController.hpp"
 #include "logic/CommandsInterpreter.hpp"
@@ -154,6 +155,14 @@ void Engine::initializeClient() {
         },
         true
     ));
+
+    keepAlive(this->input->addKeyCallback(Keycode::ESCAPE, [this]() {
+        auto& menu = *gui->getMenu();
+        if (menu.hasOpenPage() && menu.back()) {
+            return true;
+        }
+        return false;
+    }));
 }
 
 void Engine::initialize(CoreParameters coreParameters) {

src/logic/scripting/lua/libs/libgui.cpp

@@ -57,7 +57,7 @@ DocumentNode get_document_node(lua::State* L, int idx) {
 static int l_menu_back(lua::State* L) {
     auto node = get_document_node(L);
     if (auto menu = dynamic_cast<Menu*>(node.node.get())) {
-        menu->back();
+        return lua::pushboolean(L, menu->back());
     }
     return 0;
 }