refactor collection filters with django_filters

This MR aims to re-implement existing collection filters in api viewsets that are implemented in get_queryset methods with django-filter filtersets.

This has multiple advantages:

• DRF will auto-generate a filter form for the filterset fields when browsing the API with the browser, making it easier to browse & filter collections.
• Filter values can easily be validated and most are validated out-of-the-box.
• Filter documentation can be added per filter.
• django_filter is supported by drf-spectecular, which will generate a nice and tidy OpenAPI documentation for us.

program/views.py

@@ -709,7 +709,8 @@ class APINoteViewSet(viewsets.ModelViewSet):
             return Response(status=status.HTTP_400_BAD_REQUEST)
 
         serializer = NoteSerializer(
-            data=request.data, context={"user_id": request.user.id}
+            data={"show": show_pk, "timeslot": timeslot_pk} | request.data,
+            context={"user_id": request.user.id},
         )
 
         if serializer.is_valid():