Return correct hit-test values for title bar buttons on Windows (#4994)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/widgets/helper/TitlebarButton.hpp

@@ -23,6 +23,24 @@ public:
     TitleBarButtonStyle getButtonStyle() const;
     void setButtonStyle(TitleBarButtonStyle style_);
 
+    /// Simulate a `mouseEnter` event.
+    void ncEnter();
+
+    /// Simulate a `mouseLeave` event.
+    void ncLeave();
+
+    /// Simulate a `mouseMove` event.
+    /// @param at a local position relative to this widget
+    void ncMove(QPoint at);
+
+    /// Simulate a `mousePress` event with the left mouse button.
+    /// @param at a local position relative to this widget
+    void ncMousePress(QPoint at);
+
+    /// Simulate a `mouseRelease` event with the left mouse button.
+    /// @param at a local position relative to this widget
+    void ncMouseRelease(QPoint at);
+
 protected:
     void paintEvent(QPaintEvent *) override;