Add autofixing of lint warnings for specific packages/files

[mcmire]

Explanation

Currently, there are a ton of lint warnings, and it would be good to address them sooner rather than later.

The good thing is that many of these warnings can be autofixed — but only if they are turned into errors first. So, what we could do is open eslint.config.mjs, change all of the rules that are configured to produce warnings to produce errors instead ("warn" -> "error"), then run yarn lint:eslint --fix and take care of them in one fell swoop.

However, if we took this approach, approving such a PR would likely take a while since the changes would touch a bunch of packages in this monorepo and require codeowner approval from a bunch of teams.

Instead, it would be better if we batched lint violation fixes by codeowner. That is, open PRs progressively by addressing all lint violations for packages owned by the Wallet Framework team first, then the Accounts team, then the Confirmations team, etc.

To do this, we would need a way to run ESLint on specific directories. Again, that seems easy on its own, but we'd have to repeat the step that modifies eslint.config.mjs to convert warning-producing rules to errors instead each time we wanted to make a new PR.

Instead, if would be better if we could ask our ESLint script to not only allow custom file paths to be passed in, but also convert warnings into errors for us at the same time.

That's what this PR achieves. For instance, you should be able to say:

yarn lint:eslint packages/network-controller --treat-warnings-as-errors --fix

and now ESLint will run just on network-controller files, and autofix any warnings automatically.

Manual testing steps

As stated above, you should be able to run e.g.:

yarn lint:eslint packages/network-controller --treat-warnings-as-errors --fix

and see a bunch of changes made to network-controller files that fix lint violations. (ESLint may continue to report some errors as unfixable, but that's okay.)

References

Changelog

(N/A, developer-only change)

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've highlighted breaking changes using the "BREAKING" category above as appropriate
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

[mcmire]

Blocked by #5159. No longer blocked.