Git commits in Moodle 3.11.x by Jordi Pujol Ahulló

commit 0846a76c684a2df79e83732368e956be9cc7b5cf
Author: Jordi Pujol Ahulló <jpahullo@gmail.com>
Date:   Mon, 26 Oct 2020 23:57:25 +0800
Tag:    v3.11.0-beta

MDL-70038 assign: add suport for pdftoppm tool