Add severity support for vso formatter

[pfoedermayr]

PR checklist

• Addresses an existing issue: VSO formatter should report severity of rule violations #4248
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Updated the vso formatter to include the severity of the failure.
(Severity warning was hard-coded)

CHANGELOG.md entry:

[enhancement] vso formatter now reports severity of rule failures

[palantirtech]

Thanks for your interest in palantir/tslint, @pfoedermayr! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[JoshuaKGoldberg]

Thanks @pfoedermayr!

This actually is a breaking change - some build setups might have a dependency on errors still being warnings. This change should go in, but we should wait until we're sure we're about to release a new major version (6.0, presumably).

#4281 would be nice to have as well, so we can let folks get back to the old behavior.

[rmorrin]

I appreciate that this may be a breaking change and might have to wait until a major version release, but is there any timeframe of when this may be added?

We have been able to workaround this by piping output to a separate script which logs vso commands with the correct severity based on ERROR/WARNING report from tslint. This works, but obviously an official solution would be preferred.

[JoshuaKGoldberg]

Removing the Type: Breaking Change label per #4811. Now ready to merge! (once the CircleCI build unfreezes...)

[JoshuaKGoldberg]

Hmm, @adidahiya - any idea how to get this build restarted? I don't have permissions to merge.

[JoshuaKGoldberg]

ci/circleci: clean-lockfile

😢

[adidahiya]

thanks for the PR @pfoedermayr!