add "out of visible range" arrow for box plots

We would like to request an option to enable "out of visible range" arrows for boxplots. See below screenshot for an example:

The intention is to show the reader that the range was intentionally chosen to focus on the middle quartiles, as the max and min values are far out.

It would also be interesting to see this for scatter plots, but this a second priority.

首先定位 plotly.py 中箱线图的实现及其选项定义，然后检查可见范围和异常极值是如何表示的。当某个选项能够为可见范围之外的箱线图值显示箭头，同时保持对中间四分位数的关注时，此更改即完成；散点图属于优先级较低的后续工作。