Add opacity (transparency) to hover box / Allow it to be outside the plot

Plotly hover box has no transparency to it, which causes it to cover other data points, compromising the visual analysis of the data. Example:

Ideally it would allow box transparency like these one from dygraphs, which displays the hover text but does not cover/hide the region beneath it (http://dygraphs.com/tests/legend-values.html)

Additionaly, it could be great to have the possibility to show the tooltip/hover box information outside the plot, again to not cover any part of the plot and enable clear visual inspection. Another example from dygraphs:

Highcharts and dygraphs have those options as default.

There is some related discussion/request here: https://community.plotly.com/t/custom-hovertext-obstructs-plot-view-opacity-bottom-of-plot/9065

Changes like these would allow Plotly to be an excellent tool for financial plots and to be adopted by many more analysts from finance field.

Plotly is the best graphing tool in my opinion and I would like to stick to it, so I really appreciate if you can consider this request. Thank you for the awesome work.

未指定文件、测试或入口点。首先定位 repository 中 hover-box 的实现并查看链接的社区讨论，然后将所请求的透明度行为和绘图区域外行为与 dygraphs 示例进行比较。当两种悬停显示选项都能正常工作且不会遮挡绘制的数据时，即视为完成。