Squad

This 1.76.1 release adds `download_url` attribute to attachments block.
It is better if the client already knows the url to download such attachments.

This 1.76 release adds REST API endpoints to download TestRun attachments.

This 1.75.1 release fixes 2 small bugs from past release.

First one is to avoid getting build_name from oe builds and the second bug fix is related
to loading projects with builds without status objects associated.

The latter would only happen on SQUAD instances older than 2018.

This 1.75 release fixes an important bug that has been around unnoticed for quite some time.

The bug is basically a race condition when a build is marked as finished too early, before
all testjobs results are actually done processing. The fix should address that issue.

The release also allows listing projects in group's home page by active in last N days. Within
project settings one can determine N.

There has been added support for accepting OE builds from Tuxsuite and support for squad-client
will come soon.

Complete list of changes going in:

* api/rest.py: re-add suite to failures with confidence endpoint
* ci/backend/tuxsuite.py: support oe builds
* ci/models.py: bring pending function to TestJob
* settings.py: support newer versions of django-allauth
* squad/core/models.py: Change important metadata to support custom order
* squad/frontend/views.py,squad/core/models.py: move sorting of metadata
* squad/frontend/views.py: Add support for filtering project list by age

This 1.74 release patches a couple of pages improving overall performance.

It improves loading times of build tests page, test history and build comparison by tests.

The release also removes "Test failures" page, given that there's already and API endpoint
for it and it is cumbersome to maintain an UI for it as well. Finaly, this release removes
the transitions table from build comparison page, which allowed users to query changes by
specific transitions. This is too expensive to compute in larger SQUAD instances.

Complete list of changes going in:

* api/rest.py:
* fix failures with confidence pagination
* re-add test id and test run on failures_with_confidence endpoint
* support looking release builds only
* backend/tuxsuite.py:
* avoid making extra requests when retrieving build_name
* support tuxsuite sanity tests
* core/failures.py: use past N builds instead past N tests
* core/history.py: improve history performance
* frontend/comparison.py: refactor comparison to show off regressions and fixes only
* frontend/tests.py:
* allow filtering tests by environment and suite
* catch non-existant tests
* reduce query size
* remove frontend/failures.py: there's an API endpoint for it

This release fixes a variety of bugs:

* flake8: fix misc new flake8 complaints
* frontend/templatetags: support newer versions of allauth package
* frontend/views.py: handle requests provinding invalid testrun id
* templates/notification/diff.txt.jinja2: fix typo when referencing environments from known issues