Option to choose whether we include suspended users when auto-creating groups

Test 1 Run the behat tests in group/tests/behat/auto_creation.feature Test 2 Create a course. Enrol multiple students. Suspend a few of them. Log in as an admin and visit the auto-create groups functionality Test the new setting 'Include only active enrolments' and ensure it works as expected. Test 3 Create a course. Enrol multiple students and a teacher. Suspend a few of the students. Log in as an admin. Change the capability 'moodle/course:viewsuspendedusers' to 'Prohibit' for teachers. Log in as the teacher. Check that you can not see the setting 'Include only active enrolments'. Check that when creating groups you never end up with a suspended user in one.