AA-454 and AA-470: Update language and bug fix for highlights

Since Course Highlights aren't necessarily weekly (self-paced courses),
update the language to be more generic. And then includes a bug fix to
not send highlights to learners after they have unenrolled from a course.

openedx/core/djangoapps/schedules/content_highlights.py

@@ -1,5 +1,5 @@
 """
-Contains methods for accessing weekly course highlights. Weekly highlights is a
+Contains methods for accessing course highlights. Course highlights is a
 schedule experience built on the Schedules app.
 """
 

openedx/core/djangoapps/schedules/resolvers.py

@@ -471,6 +471,7 @@ class CourseNextSectionUpdate(PrefixedDebugLoggerMixin, RecipientResolver):
         schedules = Schedule.objects.select_related('enrollment').filter(
             self.experience_filter,
             active=True,
+            enrollment__is_active=True,
             enrollment__course_id=self.course_id,
             enrollment__user__is_active=True,
             start_date__gte=target_date - course_duration,

openedx/core/djangoapps/schedules/signals.py

@@ -23,7 +23,7 @@ from openedx.core.djangoapps.schedules.models import ScheduleExperience
 from openedx.core.djangoapps.schedules.utils import reset_self_paced_schedule
 from openedx.core.djangoapps.theming.helpers import get_current_site
 from common.djangoapps.student.models import CourseEnrollment
-from common.djangoapps.student.signals import ENROLLMENT_TRACK_UPDATED
+from common.djangoapps.student.signals import ENROLL_STATUS_CHANGE, ENROLLMENT_TRACK_UPDATED
 from common.djangoapps.track import segment
 
 from .config import CREATE_SCHEDULE_WAFFLE_FLAG
@@ -61,6 +61,24 @@ def create_schedule(sender, **kwargs):  # pylint: disable=unused-argument
         ))
 
 
+@receiver(ENROLL_STATUS_CHANGE)
+def update_schedule(sender, event, user, course_id, **kwargs):  # pylint: disable=unused-argument
+    """
+    When a CourseEnrollment's status is updated, update the Schedule's active status if configured.
+    """
+    try:
+        schedule = Schedule.objects.get(enrollment__user=user, enrollment__course=course_id)
+    except Schedule.DoesNotExist:
+        # Exit since it could just be an indication of Schedules are not enabled.
+        return
+
+    if event == 'enroll':
+        schedule.active = True
+    elif event == 'unenroll':
+        schedule.active = False
+    schedule.save()
+
+
 @receiver(COURSE_START_DATE_CHANGED)
 def update_schedules_on_course_start_changed(sender, updated_course_overview, previous_start_date, **kwargs):   # pylint: disable=unused-argument
     """