fix(metric): add option to set empty cell background color (#2247) [61.0.x]#2250

nickofthyme merged 3 commits intoelastic:61.0.xelastic/elastic-charts:61.0.xfrom

nickofthyme:backport/61.0.x/pr-2247nickofthyme/elastic-charts:backport/61.0.x/pr-2247Copy head branch name to clipboard