Add interactivity for geom_pcp

It would be elegant to be able to create interactive parallel coordinate plots with plotly layered on the ggpcp library. Users should be able to select a line (or lines) and the entire line would highlight.

library(ggplot2)
data(mtcars)
mtcars_pcp <- mtcars |>
  dplyr::mutate(
    cyl = factor(cyl),
    vs = factor(vs),
    am = factor(am),
    gear = factor(gear),
    carb = factor(carb)
  ) |>
  pcp_select(1:11) |>  # select everything
  pcp_scale() |>
  pcp_arrange()

 base <- mtcars_pcp |> ggplot(aes_pcp())


 # Just the base plot:
 base + geom_pcp()

# Ideally this would allow lines to be selected 
ggplotly() 

# Or something like:
highlight_key(mtcars) |> ... (ggplot2 code) |> ggplotly()

从 issue 中描述的 geom_pcp 和 ggplotly 入口点开始，并将提议的 highlight_key 方法与使用 pcp_select、pcp_scale 和 pcp_arrange 的 ggpcp 流程进行比较。当平行坐标图支持选择一条或多条线，并以交互方式突出显示所选线的完整内容时，即表示完成。