Add more tests for docs' views

[rsebille]

Not all code branches are tested and it's mostly coverage works but it should prevent simple errors or regression while simplify adding or improving tests for those views.

There is one point to discuss, it's the FIXME in the document views.

[sarahboyce]

I aim to review this soon, in the meantime can you resolve the conflicts? 🙏
Also these new tests appear to fail, can you take a look?

[rsebille]

I aim to review this soon, in the meantime can you resolve the conflicts? 🙏 Also these new tests appear to fail, can you take a look?

Sorry for the delay, the branch is rebased.
I will try to investigate the failing tests this week-end, I must have missed something as they all pass when I use docker compose run --rm web python -m manage test but didn't find any of the usual suspects :/.