Add @static* annotations where they are missing.

Initialize all static vars that are not, most to `null`.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32650 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-customize-section.php

@@ -24,6 +24,8 @@ class WP_Customize_Section {
 	 * Used when sorting two instances whose priorities are equal.
 	 *
 	 * @since 4.1.0
+	 *
+	 * @static
 	 * @access protected
 	 * @var int
 	 */