The `ValidatorDefaults` is cumbersome, and customising it can be
annoying. Most projects use some sort of dependency injection container,
and by integrating the creation of the `Validator` with the PSR-11, we
allow users to easily customise how they create validators.
Some tasks, like overwriting the `Translator`, become a bit more
verbose, if the user is not already using a PSR-11 container, but I
think that’s a good tradeoff.
