Implements enableMessageNames

[arcanis]

What's the problem this PR addresses?

I can understand why some people would prefer to reclaim some of their terminal with by removing the message names from the output. I still think we should add them by default (otherwise they'd be completely pointless, since the people who would most need them would be unaware of their existence), but power users should have a way to skip them.

How did you fix it?

A new enableMessageNames setting now lets you remove the message names from the output. As any setting, it can be configured in the home .yarnrc.yml file, in a project-local one, or via the environment.

Checklist

• I have read the Contributing Guide.

• I have set the packages that need to be released for my changes to be effective.

• I will check that all automated PR checks pass before the PR gets reviewed.