MDL-74841 behat: Label behat generators use UI

Replace steps that manually add Label instances via the UI and use
Behat generators. This improves the speed of Behat test runs. Fix
for failing test.

course/tests/behat/section_visibility.feature

@@ -96,6 +96,7 @@ Feature: Show/hide course sections
     And I should not see "Topic 2" in the "region-main" "region"
     And I should see "Topic 1" in the "region-main" "region"
 
+  @javascript
   Scenario: Students can not navigate to restricted sections
     Given I am on "Course 1" course homepage
     Given I navigate to "Settings" in current page administration
@@ -104,7 +105,7 @@ Feature: Show/hide course sections
       | Enable completion tracking | Yes |
     And I press "Save and display"
     And the following "activities" exist:
-      | activity | course | section | intro      | completion |
+      | activity | course | section | name       | completion |
       | label    | C1     | 1       | Test label | 1          |
     And I edit the section "2"
     And I expand all fieldsets