pie labels/values aren't relayed in event_data()

At least the customdata workaround exists, but we should do a better job relaying more information (do we 'black-list' pt.data/pt._fullData and let everything else through)? https://codepen.io/cpsievert/pen/rNNZpVo

library(shiny)

ui <- fluidPage(
  plotlyOutput("category"),
  verbatimTextOutput("info")
)

server <- function(input, output) {
  
  output$category <- renderPlotly({
    sales %>%
      count(category, wt = sales) %>%
      plot_ly() %>%
      add_pie(labels = ~category, values = ~n)
  })
  
  output$info <- renderPrint({
    event_data("plotly_click")
  })
  
}

shinyApp(ui, server)

Start with the provided Shiny example and the event_data("plotly_click") entry point, comparing the pie chart output with the customdata workaround. Determine which pie labels and values should be relayed and whether the existing pt.data and pt._fullData handling excludes them. Done means the intended fields appear in the event data for the example.