Enable pre-selected option in tau_legend

[happyshows]

Hi,

There are a few cases I want to preselect some values when chart it rendered. Having this feature will allow me to drill through from other diagrams to here. For example, I clicked a cell in DT package, fetch the filter condition, and then show all relevant data in a bar chart (while still maintaining the capability to see the whole dataset)
maybe something like
data %>%
tauchart %>%
tau_bar('XXX','YYY',color = 'ColorColumn') %>%
tau_legend(selected = sessionObj$DTselectedCol)

Thanks.