This adds [commitlint](https://npm.im/@commitlint/cli) to the project which validates commit messages against the [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) spec via a preset.
Removed the [pre-commit](https://npm.im/pre-commit) package as it has not been updated in six (6) years; replaced with [husky](https://typicode.github.io/husky/) which is widely-used and full-featured.
Customized commitlint so that it will allow commit messages lines of arbitrary length; this is set to 100 by default, but is not in the specification. If someone has a good reason that we _shouldn't_ disable that rule, please say something!
Closes#17844
