feat: add plot/vega/scale/threshold#11117

gururaj1512 wants to merge 2 commits intostdlib-js:refactor/plotstdlib-js/stdlib:refactor/plotfrom

gururaj1512:refactor/plot-vega-scale-thresholdgururaj1512/stdlib:refactor/plot-vega-scale-thresholdCopy head branch name to clipboard