Media: In wp_read_image_metadata() make sure that IPTC keywords are UTF8 encoded.

Prevents missing `_wp_attachment_metadata` when an image contains keywords with latin extended characters.

Fixes #35316.
Built from https://develop.svn.wordpress.org/trunk@36429


git-svn-id: http://core.svn.wordpress.org/trunk@36396 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/kses.php

@@ -1581,6 +1581,19 @@ function wp_kses_post( $data ) {
 	return wp_kses( $data, 'post' );
 }
 
+/**
+ * Navigates through an array, object, or scalar, and sanitizes content for
+ * allowed HTML tags for post content.
+ *
+ * @since 4.4.2
+ *
+ * @param mixed $value The array or string to filter.
+ * @return mixed $value The filtered content.
+ */
+function wp_kses_post_deep( $data ) {
+	return map_deep( $data, 'wp_kses_post' );
+}
+
 /**
  * Strips all of the HTML in the content.
  *