MDL-51354 report/log: Add context sensitive help

Adds context sensitive help to the Reports > Logs page (both admin
and course level) to help users understand how the filters will
affect their search.

lang/en/moodle.php

@@ -557,7 +557,10 @@
 $string['edulevelother'] = 'Other';
 $string['edulevelteacher'] = 'Teaching';
 $string['edulevelparticipating'] = 'Participating';
-$string['edulevel'] = 'Educational level';
+$string['edulevel'] = 'All events';
+$string['edulevel_help'] = '* Teaching - actions performed by a teacher, e.g. updating a resource
+* Participating - actions performed by a student, e.g. posting in a forum
+* Other - actions performed by a user with a role other than teacher or student';
 $string['email'] = 'Email address';
 $string['emailalreadysent'] = 'A password reset email has already been sent. Please check your email.';
 $string['emailactive'] = 'Email activated';

report/log/classes/renderer.php

@@ -167,7 +167,7 @@ public function report_selector_form(report_log_renderable $reportlog) {
         // Add edulevel.
         $edulevel = $reportlog->get_edulevel_options();
         echo html_writer::label(get_string('edulevel'), 'menuedulevel', false, array('class' => 'accesshide'));
-        echo html_writer::select($edulevel, 'edulevel', $reportlog->edulevel, false);
+        echo html_writer::select($edulevel, 'edulevel', $reportlog->edulevel, false).$this->help_icon('edulevel');
 
         // Add reader option.
         // If there is some reader available then only show submit button.