feat: Adds Histogram chart migration logic (#28780)

superset-frontend/plugins/plugin-chart-echarts/src/Histogram/buildQuery.ts

@@ -25,8 +25,10 @@ export default function buildQuery(formData: HistogramFormData) {
   return buildQueryContext(formData, baseQueryObject => [
     {
       ...baseQueryObject,
+      extras: { where: `${column} IS NOT NULL` },
       columns: [...groupby, column],
       post_processing: [histogramOperator(formData, baseQueryObject)],
+      metrics: undefined,
     },
   ]);
 }

superset-frontend/plugins/plugin-chart-echarts/src/Histogram/transformProps.ts

@@ -136,9 +136,10 @@ export default function transformProps(
   const echartOptions: EChartsOption = {
     grid: {
       ...defaultGrid,
-      bottom: 30,
-      left: 30,
-      right: 30,
+      left: '5%',
+      right: '5%',
+      top: '10%',
+      bottom: '10%',
     },
     xAxis: {
       data: xAxisData,