Author: David Monllao
MDL-55191 search: Generate an search result viewed event
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e71061a22b5bc3646fbb0ec515628e8c2623f091
http://github.com/moodle/moodle/commit/e71061a22b5bc3646fbb0ec515628e8c2623f091
+ 3.2 en [eventsearchresultsviewed,core]