feat!: drop legacy course home view and related code

This was the "outline tab" view of the course. Preceded by the
course info view, succeeded by the MFE outline tab.

In addition to the course home view itself, this drops related
features:
- Legacy version of Course Goals (MFE has a newer implementation)
- Course home in-course search (MFE has no search)

The old course info view and course about views survive for now.

This also drops a few now-unused feature toggles:
- course_experience.latest_update
- course_experience.show_upgrade_msg_on_course_home
- course_experience.upgrade_deadline_message
- course_home.course_home_use_legacy_frontend

With this change, just the progress and courseware tabs are still
supported in legacy form, if you opt-in with waffle flags. The
outline and dates tabs are offered only by the MFE.

AA-798

(This is identical to previous commit be5c1a6, just reintroduced
now that the e2e tests have been fixed)

openedx/features/calendar_sync/views/calendar_sync.py

@@ -8,7 +8,6 @@ import json
 from django.contrib.auth.decorators import login_required
 from django.http import HttpResponse
 from django.shortcuts import redirect
-from django.urls import reverse
 from django.utils.decorators import method_decorator
 from django.views.decorators.csrf import ensure_csrf_cookie
 from django.views.generic import View
@@ -22,6 +21,7 @@ from openedx.features.calendar_sync.api import (
     subscribe_user_to_calendar,
     unsubscribe_user_to_calendar
 )
+from openedx.features.course_experience import course_home_url
 
 
 class CalendarSyncView(View):
@@ -54,4 +54,4 @@ class CalendarSyncView(View):
         else:
             return HttpResponse('Toggle data was not provided or had unknown value.',
                                 status=status.HTTP_422_UNPROCESSABLE_ENTITY)
-        return redirect(reverse('openedx.course_experience.course_home', args=[course_id]))
+        return redirect(course_home_url(course_key))