Widgets: Let Custom HTML widget be "wide" as the Text widget is.

Also update `WP_Customize_Widgets::$core_widget_id_bases` with the new list of core widgets.

Props obenland, westonruter.
See #40907, #40951.


git-svn-id: https://develop.svn.wordpress.org/trunk@41000 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/widgets/class-wp-widget-custom-html.php

@@ -38,7 +38,10 @@ class WP_Widget_Custom_HTML extends WP_Widget {
 			'description' => __( 'Arbitrary HTML code.' ),
 			'customize_selective_refresh' => true,
 		);
-		$control_ops = array();
+		$control_ops = array(
+			'width' => 400,
+			'height' => 350,
+		);
 		parent::__construct( 'custom_html', __( 'Custom HTML' ), $widget_ops, $control_ops );
 	}