MDL-55915 enrol_manual: let fullname()know if user has viewfullnames cap

fullname() relies on its second parameter to determine wheter it should use fullnamedisplay or alternativefullnameformat.
We need to check for moodle/site:viewfullnames capability and pass true as the second parameter to fullname() whereever
the user has this capability.

enrol/manual/ajax.php

@@ -80,9 +80,10 @@ switch ($action) {
         } else {
             $useroptions['link'] = false;
         }
+        $viewfullnames = has_capability('moodle/site:viewfullnames', $context);
         foreach ($outcome->response['users'] as &$user) {
             $user->picture = $OUTPUT->user_picture($user, $useroptions);
-            $user->fullname = fullname($user);
+            $user->fullname = fullname($user, $viewfullnames);
             $fieldvalues = array();
             foreach ($extrafields as $field) {
                 $fieldvalues[] = s($user->{$field});

enrol/manual/manage.php

@@ -37,6 +37,7 @@ $context = context_course::instance($course->id, MUST_EXIST);
 require_login($course);
 $canenrol = has_capability('enrol/manual:enrol', $context);
 $canunenrol = has_capability('enrol/manual:unenrol', $context);
+$viewfullnames = has_capability('moodle/site:viewfullnames', $context);
 
 // Note: manage capability not used here because it is used for editing
 // of existing enrolments which is not possible here.
@@ -74,7 +75,9 @@ navigation_node::override_active_url(new moodle_url('/enrol/users.php', array('i
 $options = array('enrolid' => $enrolid, 'accesscontext' => $context);
 
 $potentialuserselector = new enrol_manual_potential_participant('addselect', $options);
+$potentialuserselector->viewfullnames = $viewfullnames;
 $currentuserselector = new enrol_manual_current_participant('removeselect', $options);
+$currentuserselector->viewfullnames = $viewfullnames;
 
 // Build the list of options for the enrolment period dropdown.
 $unlimitedperiod = get_string('unlimited');