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.