feat(spec)!: a pie / donut / funnel / treemap / sankey widget takes one measure with a dimension too — refuse two or more at values, and rename the check to checkDashboardWidgetChartMeasureArity (#21293)

feat(spec)!: a pie / donut / funnel / treemap / sankey widget takes one measure with a dimension too — refuse two or more at values, and rename the check to checkDashboardWidgetChartMeasureArity (#21293) #6095