Added i18n support to ConfirmationQuestion

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

For instance, when creating a dutch cli app, you want this to be `j` (from "Ja") instead of the english `y`.
`$answerIsTrue = stripos($answer, $this->trueAnswer) === 0;`?