feat(widgets): search affix, mod apply, blur_bg, iframe null

Wire search sidebar affix, plate moderator apply entry, user-lists
REST blur_bg, and iframe empty via aksrt_get_widget_null.

src/AKSRT/Widgets/WidgetIframe.php

@@ -31,8 +31,9 @@ class WidgetIframe extends \WP_Widget {
 		if ($raw === '') {
 			if (current_user_can('manage_options')) {
 				echo $args['before_widget']; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
-				echo '<div class="c-red muted-box mb20"><b>' . esc_html__('超级嵌入：', 'aksrt') . '</b>' .
-					esc_html__('请配置 URL 或 iframe 代码', 'aksrt') . '</div>';
+				echo function_exists('aksrt_get_widget_null')
+					? aksrt_get_widget_null(__('请配置 URL 或 iframe 代码', 'aksrt')) // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
+					: '<div class="c-red muted-box mb20"><b>' . esc_html__('超级嵌入：', 'aksrt') . '</b>' . esc_html__('请配置 URL 或 iframe 代码', 'aksrt') . '</div>';
 				echo $args['after_widget']; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
 			}
 			return;