Implement mouse-capture attribute on ui system

src/node.h

@@ -45,6 +45,7 @@ enum class kAttribute : uint16_t
     Default = const_hash("default"),
     RTL = const_hash("rtl"),
     AutoSize = const_hash("autosize"),
+    MouseCapture = const_hash("mouse-capture"),
 };
 
 enum class kWidget : uint16_t
@@ -107,6 +108,7 @@ public:
     glm::mat4 m_mvp;
     bool m_mouse_inside = false;
     bool m_flood_events = false;
+    bool m_force_mouse_capture = false;
     bool m_capture_children = true; // wether to capture children events when xx_capture() is used
     bool m_destroyed = false;