feat: Distinguish failed from not-applied checkers

[jennifer-richards]

Fixes #4346

With this change, passing checks are unchanged, still "Your Internet-Draft has been verified to pass the submission checks."

and the wording for a failed test is now "Your Internet-Draft failed at least one submission check."

If no checks were applied, it says so, "No submission checks were applied to your Internet-Draft." The visual style is still alert-warning because this is not a healthy situation for a submission.

This also refactors and reuses the latest_checks() method which should give better results if checks are applied multiple times (though afaik this does not happen often if at all).

[codecov]

Codecov Report

Merging #6220 (ad28c54) into main (aa955f0) will decrease coverage by 0.01%.
Report is 15 commits behind head on main.
The diff coverage is 68.18%.

❗ Current head ad28c54 differs from pull request most recent head 6d5c644. Consider uploading reports for the commit 6d5c644 to get more accurate results

@@            Coverage Diff             @@
##             main    #6220      +/-   ##
==========================================
- Coverage   88.68%   88.68%   -0.01%     
==========================================
  Files         290      290              
  Lines       40300    40306       +6     
==========================================
+ Hits        35742    35747       +5     
- Misses       4558     4559       +1     

Files Changed	Coverage Δ
ietf/name/models.py	100.00% <ø> (ø)
ietf/submit/utils.py	90.17% <56.25%> (-0.08%)	⬇️
ietf/submit/models.py	93.96% <100.00%> (ø)
ietf/submit/views.py	84.65% <100.00%> (+0.05%)	⬆️

... and 2 files with indirect coverage changes

[rjsparks]

This feels like we're missing some tests.

[rjsparks]

@jennifer-richards : please merge main in again

[jennifer-richards]

This feels like we're missing some tests.

I agree. The existing tests of submission_status() are mixed in with other tests. I've started a SubmissionStatusTests class with a test to exercise the new stuff.