Git commits in Moodle 3.9.x by Alfonso Salces

commit a950ed04a718a64eea2fdab7115658cabffb1398
Author: Alfonso Salces <alfonso.salces@moodle.com>
Date:   Tue, 12 Apr 2022 18:26:59 +0800
Tag:    v3.9.15

MDL-74674 core: create notification generators