[Intl] Added round support for ROUND_CEILING, ROUND_FLOOR, ROUND_DOWN, ROUND_UP
bug #9895 [Intl] Added round support for ROUND_CEILING, ROUND_FLOOR, ROUND_DOWN, ROUND_UP (pamil)

This PR was squashed before being merged into the 2.4 branch (closes #9895).

Discussion
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[Intl] Added round support for ROUND_CEILING, ROUND_FLOOR, ROUND_DOWN, ROUND_UP

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | yes
| BC breaks?    | no, actually it fixes some
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9838
| License       | MIT
| Doc PR        |

Adds support for 4 unsupported rounding modes (ROUND_CEILING, ROUND_FLOOR, ROUND_DOWN, ROUND_UP) in `NumberFormatter` from `Intl` component, so that `Symfony\Component\Form\Extension\Core\DataTransformer\IntegerToLocalizedStringTransformer` won't throw exception if `lib-intl` is not installed.

Commits
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f5fee9a [Intl] Added round support for ROUND_CEILING, ROUND_FLOOR, ROUND_DOWN, ROUND_UP