feat(charts): add subtitle option and metric customization controls (#32975)

superset-frontend/plugins/plugin-chart-echarts/src/BigNumber/BigNumberWithTrendline/controlPanel.tsx

@@ -26,7 +26,12 @@ import {
   getStandardizedControls,
   temporalColumnMixin,
 } from '@superset-ui/chart-controls';
-import { headerFontSize, subheaderFontSize } from '../sharedControls';
+import {
+  headerFontSize,
+  subheaderFontSize,
+  subtitleFontSize,
+  subtitleControl,
+} from '../sharedControls';
 
 const config: ControlPanelConfig = {
   controlPanelSections: [
@@ -134,6 +139,8 @@ const config: ControlPanelConfig = {
         ['color_picker', null],
         [headerFontSize],
         [subheaderFontSize],
+        [subtitleControl],
+        [subtitleFontSize],
         ['y_axis_format'],
         ['currency_format'],
         [

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

@@ -66,6 +66,8 @@ export default function transformProps(
     metric = 'value',
     showTimestamp,
     showTrendLine,
+    subtitle = '',
+    subtitleFontSize,
     aggregation,
     startYAxisAtZero,
     subheader = '',
@@ -302,6 +304,8 @@ export default function transformProps(
     formatTime,
     formData,
     headerFontSize,
+    subtitleFontSize,
+    subtitle,
     subheaderFontSize,
     mainColor,
     showTimestamp,