Patch View to be generic to support djangorestframework-stubs?

[henribru]

This isn't actually needed for django-stubs, but djangorestframework-stubs uses generic views, so could we add it to the classes monkeypatched by django_stubs_ext? If so I'd be happy to create a PR for that

[henribru]

Or perhaps we could allow passing in additional classes to monkeypatch?

[sobolevn]

Yes, extra classes to monkeypatch seem like a good idea.