feat: enable Toggle State API in CMS (openedx#33598)

The Toggle State API lets global staff users inspect the
computed state of all toggles, which can be a helpful
short-circuit to reasoning about the various layers of
configuration that feed into edx-platform.

Currently the API is only enabled in LMS. This would enable
it in CMS as well. Although LMS and CMS share many of the same base settings,
they each have their own overrides and extensions to configuration,
so exposing a separate CMS Toggle State API will be beneficial.

cms/urls.py

@@ -67,6 +67,7 @@
     path('not_found', contentstore_views.not_found, name='not_found'),
     path('server_error', contentstore_views.server_error, name='server_error'),
     path('organizations', OrganizationListView.as_view(), name='organizations'),
+    path('api/toggles/', include('openedx.core.djangoapps.waffle_utils.urls')),
 
     # noop to squelch ajax errors
     path('event', contentstore_views.event, name='event'),