We don't have much use for it anymore, let's use ElementTree everywhere
for consistency.

xmltodict was already on the way out for the deposit, and the latest
libexpat security update broke it entirely when dealing with namespaces,
which means we cannot use it until this is addressed.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1006317

Functional changes of this commit:

1. No more writes to the 'metadata' jsonb column in the DB (as it
   strongly depends on xmltodict)
2. ServiceDocumentDepositClient always outputs a list of collections,
   instead of None/dict/List[dict] depending on the number of
   collections (artefact of using xmltodict, which is replaced by proper
   parsing)

python3-django all 1:1.11.29-1~deb10u1 (debian stable) and `django.urls.reverse` are not
going well together in test apparently.

[1] https://jenkins.softwareheritage.org/job/debian/job/packages/job/DDEP/job/gbp-buildpackage/92/

SWORD doesn't require them to be the same, and IMO it is clearer
if we keep them separate.

Multiple existing tests were not properly configured [1] and checking multiple times the same scenario.
This makes sure this will not happen again.

[1] D4057 D4060

Related to T2610

- blackify all the python files,
- enable black in pre-commit,
- add a black tox environment.

David Douard authored 5 years ago and Antoine R. Dumont committed 5 years ago

in favor a simpler Choice in DepositRequest.

Summary: Part of T1261

Test Plan: Still running 104 tests after the change

Reviewers: ardumont

Differential Revision: https://forge.softwareheritage.org/D525

This takes care of current limitations:
- duplicated elements are stored as list (and no longer dropped)
- drop extra namespace in key names
- it's generic

Close T1131

Closes T934

As we deactivate the checks in tests, all deposit are now passed to
'ready-for-checks' instead of ready.

Related T857

Now, we use real basic archives for testing purpose.

- Fix error in PUT EM_IRI implementation
- Improve test docstrings
- Separate delete tests from update ones