text: Title: 建议增加MiddlePressMouse、MiddleReleaseMouse、MiddleDragDrop方法
  Body: 建议大佬，审阅增加以下封装方法，多谢啦！
  uiautomation line1916 增加鼠标中键按压释放方法MiddlePressMouse、MiddleReleaseMouse
                       line2010增加拖移中键方法MiddleDragDrop
  
  def MiddlePressMouse(x: int, y: int, waitTime: float = OPERATION_WAIT_TIME) -> None:
      """
      Press middle mouse.
      x: int.
      y: int.
      waitTime: float.
      """
      SetCursorPos(x, y)
      screenWidth, screenHeight = GetScreenSize()
      mouse_event(MouseEventFlag.MiddleDown | MouseEventFlag.Absolute, x * 65535 // screenWidth, y * 65535 // screenHeight, 0, 0)
      time.sleep(waitTime)
  
  
  def MiddleReleaseMouse(waitTime: float = OPERATION_WAIT_TIME) -> None:
      """
      Release middle mouse.
      waitTime: float.
      """
      x, y = GetCursorPos()
      screenWidth, screenHeight = GetScreenSize()
      mouse_event(MouseEventFlag.MiddleUp | MouseEventFlag.Absolute, x * 65535 // screenWidth, y * 65535 // screenHeight, 0, 0)
      time.sleep(waitTime)
  
  
  def MiddleDragDrop(x1: int, y1: int, x2: int, y2: int, moveSpeed: float = 1, waitTime: float = OPERATION_WAIT_TIME) -> None:
      """
      Simulate mouse middle button drag from point x1, y1 drop to point x2, y2.
      x1: int.
      y1: int.
      x2: int.
      y2: int.
      moveSpeed: float, 1 normal speed, < 1 move slower, > 1 move faster.
      waitTime: float.
      """
      MiddlePressMouse(x1, y1, 0.05)
      MoveTo(x2, y2, moveSpeed, 0.05)
      MiddleReleaseMouse(waitTime)
  
  @yinkaisheng 
  