converted throttling tests asserts to pytest

converted negotiation tests asserts to pytest

converted multi-table-inheritence test asserts to pytest

* converted urlpatterns test asserts to pytest

* converted test utils asserts to pytest

* removed extra newlines

* Add test for disabling declared fields on child
* Check that declared base field is not in attrs
* Update meta inheritance docs to include serializer
* Test that meta fields cannot be declared as None
* Add docs example for declarative field disabling

modify documenting-your-api docs topic with additional package

added drf-flexfields addon info

Add DRF-Base64 to third-party serializers

Add DRF-Base64, which provides serializers to handle base64-encoded files, to third-party serializers packages

Add drf-schema-adapter to 3rd party metadata mods

docs: typo fix: it's -> its

* add failing testcase for breadcrumb suffixes missing when using ModelViewSets

* fix get_breadcrumbs to honor overridden get_view_name and keep viewset suffixes

* ensure suffixes are appended in breadcrumb util

The order of the line break was wrong

Add drf-oidc-auth to docs

converted authentication test asserts to pytest

Updated Link ti Django Docs

The Url to the settings/#caches Link changed in Django documentation.

Just makes the topic page easier to find.

Closes #1673