IFrame widget improvements (#15483)

changes - 
- make iframe side panel to match others -- ie use SidePanelHeader for
title
- make url optional in configuration to match that of the other widgets
(allow partial saves) - render No data status when error or no url
- split widget sizes into two -- graph widget sizes and widget sizes
(graph widgets are a subset of chart widgets)

packages/twenty-front/src/modules/page-layout/utils/getWidgetSize.ts

@@ -1,11 +1,11 @@
 import { DEFAULT_WIDGET_SIZE } from '@/page-layout/constants/DefaultWidgetSize';
-import { WIDGET_SIZES } from '@/page-layout/constants/WidgetSizes';
+import { GRAPH_WIDGET_SIZES } from '@/page-layout/constants/GraphWidgetSizes';
 import { type GraphType } from '~/generated/graphql';
 
 export const getWidgetSize = (
   graphType: GraphType,
   type: 'default' | 'minimum',
 ): { w: number; h: number } => {
-  const sizeConfig = WIDGET_SIZES[graphType] ?? DEFAULT_WIDGET_SIZE;
+  const sizeConfig = GRAPH_WIDGET_SIZES[graphType] ?? DEFAULT_WIDGET_SIZE;
   return sizeConfig[type];
 };