[PATCH 0/4] Add submission relations

[Mete Polat]

This patch introduces the ability to view relations between submissions by
creating and updating them via the REST API.

Changes since v3:
- Redesign relations part in submissions view
- Add missing fixes tag in 'docs: Add missing series index schema'
- Show more than just the submission ids in the REST API (by Daniel Axtens)
- Add a "by" column to SubmissionRelation to identify who is doing what
- Restrict relation changes to submissions that are already part of another
  relation (returns HTTP code 409 CONFLICT)
- Add test for conflicting submissions in relations
- Clarify MaintainerPermission with some comments
- Optimize db access in submission.html and in the relations REST API
- Remove submission_count ordering for relations
- Remove RelationError openAPI schema (formerly used for bulk operations)

Note:
- Kept one-to-many instead of many-to-many for submissions in relations.
- Kept all tests in test_relation. They are not that comprehensive. They just
  test the same thing for different users (maintainer/non-maintainer/anonymous).
  I had to write all combinations manually as not every python version we
  support allows generating test cases automatically. They also helped me a lot
  in finding permission issues.

Mete Polat (4):
  ui, templates: Combine series and related row
  models, templates: Add submission relations
  docs: Add missing series index schema
  REST: Add submission relations

 docs/api/schemas/latest/patchwork.yaml        | 278 +++++++++++++++++
 docs/api/schemas/patchwork.j2                 | 290 ++++++++++++++++++
 docs/api/schemas/v1.0/patchwork.yaml          |   5 +
 docs/api/schemas/v1.1/patchwork.yaml          |   5 +
 docs/api/schemas/v1.2/patchwork.yaml          | 278 +++++++++++++++++
 htdocs/css/style.css                          |   2 +-
 patchwork/api/embedded.py                     |  39 +++
 patchwork/api/index.py                        |   1 +
 patchwork/api/relation.py                     | 121 ++++++++
 .../migrations/0038_submission_relations.py   |  30 ++
 patchwork/models.py                           |  16 +
 patchwork/templates/patchwork/submission.html |  94 ++++--
 patchwork/tests/api/test_relation.py          | 181 +++++++++++
 patchwork/tests/utils.py                      |  15 +
 patchwork/urls.py                             |  11 +
 patchwork/views/patch.py                      |   7 +
 ...submission-relations-c96bb6c567b416d8.yaml |  10 +
 17 files changed, 1351 insertions(+), 32 deletions(-)
 create mode 100644 patchwork/api/relation.py
 create mode 100644 patchwork/migrations/0038_submission_relations.py
 create mode 100644 patchwork/tests/api/test_relation.py
 create mode 100644 releasenotes/notes/add-submission-relations-c96bb6c567b416d8.yaml

-- 
2.24.0