Use rest_is_field_included when determining which additional fields to include to permit filtering by nested field properties. Props Dudo, kadamwhite, TimothyBlynJacobs. Fixes #49648. Built from https://develop.svn.wordpress.org/trunk@47511 git-svn-id: http://core.svn.wordpress.org/trunk@47286 1a063a9b-81f0-0310-95a4-ce76da25c4cd