Add `$depth` parameter to the `nav_menu_css_class`, `nav_menu_item_id`, and `nav_menu_link_attributes` filters.

Fixes #19064
Props cyclometh, chriscct7, johnbillion

Built from https://develop.svn.wordpress.org/trunk@30358


git-svn-id: http://core.svn.wordpress.org/trunk@30357 1a063a9b-81f0-0310-95a4-ce76da25c4cd