Gui: prevent hover tooltip from covering menu items (#22019)

* fix #21330: prevent hover tooltip from covering menu items
Instead of showing the tooltip at the mouse cursor,
it is now displayed to the right of the corresponding
menu option, avoiding overlap with the menu itself.

* Update src/Gui/Action.cpp

---------

Co-authored-by: Chris Hennes <chennes@pioneerlibrarysystem.org>

src/Gui/Action.cpp

@@ -606,9 +606,37 @@ void ActionGroup::onActivated (QAction* act)
     }
 }
 
-void ActionGroup::onHovered (QAction *act)
+/**
+ * Shows tooltip at the right side when hovered.
+ */
+void ActionGroup::onHovered(QAction *act)
 {
-    QToolTip::showText(QCursor::pos(), act->toolTip());
+    const auto topLevelWidgets = QApplication::topLevelWidgets();
+    QMenu* foundMenu = nullptr;
+
+    for (QWidget* widget : topLevelWidgets) {
+        QList<QMenu*> menus = widget->findChildren<QMenu*>();
+
+        for (QMenu* menu : menus) {
+            if (menu->isVisible() && menu->actions().contains(act)) {
+                foundMenu = menu;
+                break;
+            }
+        }
+
+        if (foundMenu) {
+            break;
+        }
+
+    }
+
+    if (foundMenu) {
+        QRect actionRect = foundMenu->actionGeometry(act);
+        QPoint globalPos = foundMenu->mapToGlobal(actionRect.topRight());
+        QToolTip::showText(globalPos, act->toolTip(), foundMenu, actionRect);
+    } else {
+        QToolTip::showText(QCursor::pos(), act->toolTip());
+    }
 }