MDL-82109 notes: include link to add site note if user has capability.

notes/index.php

@@ -176,9 +176,11 @@
         $USER->id
     );
 
-} else {  // Normal course.
-    $view = has_capability('moodle/notes:view', context_system::instance());
-    note_print_notes('<a name="sitenotes"></a>' . $strsitenotes, 0, $view, 0, $userid, NOTES_STATE_SITE, 0);
+} else {
+    // Site course.
+    $addid = has_capability('moodle/notes:manage', $systemcontext) ? SITEID : 0;
+    $view = has_capability('moodle/notes:view', $systemcontext);
+    note_print_notes('<a name="sitenotes"></a>' . $strsitenotes, $addid, $view, 0, $userid, NOTES_STATE_SITE, 0);
     echo '<a name="coursenotes"></a>';
 
     if (!empty($userid)) {

notes/tests/behat/site_notes.feature

@@ -0,0 +1,16 @@
+@core @core_notes
+Feature: Add notes to site users
+  In order to share information with other users
+  As an admin
+  I need to add notes to site user accounts
+
+  Scenario: Add a user site note
+    Given the following "users" exist:
+      | username | firstname | lastname | email                |
+      | student1 | Student   | 1        | student1@example.com |
+    When I am on the "student1" "user > profile" page logged in as "admin"
+    And I follow "Notes"
+    And I follow "Add a new note"
+    And I set the field "Content" to "Student 1 needs to pick up his game"
+    And I press "Save changes"
+    Then I should see "Student 1 needs to pick up his game" in the ".notelist" "css_element"