Make twig/extra-bundle optional

[wbloszyk]

Subject

sonata-project/intl-bundle and twig/intl-extra register format_datetime what make them in conflict.
twig/extra-bundle require-dev twig/intl-extra and auto-register it in twig. This will not allow use last SonataAdminBundle releases with some bundles like ecommerce.

I am targeting this branch, because this change respect BC.

Closes #6169.

Changelog

### Changed
- Move `twig/extra-bundle` from `require` to `suggest`

### Fixed
- Fix error with missing `u` filter when `twig/extra-bundle` is not registred

[SonataCI]

Could you please rebase your PR and fix merge conflicts?

[SonataCI]

Could you please rebase your PR and fix merge conflicts?

[wbloszyk]

I found another bug here :(
All working correct but minimum one of bundles with this change must be register before TwigBundle. Otherwise compiler pass from twig will not register StringExtension as twig.extension.

Update

Add priority resolve this issue:

$container->addCompilerPass(new TwigStringExtensionCompilerPass(), PassConfig::TYPE_BEFORE_OPTIMIZATION, 1);

[phansys]

Note: PHPStan is failing.

[wbloszyk]

PHPStan failing becouse CoreBundle id optional. I think this should be fix in dev-kit.

[jordisala1991]

No, it is fixed here: #6161

[VincentLanglet]

Let's merge this then ; the phpstan will be fixed.

[jordisala1991]

Thank you @wbloszyk