Replace PageableManagerInterface in favor for PageableInterface

[wbloszyk]

Subject

I am targeting this branch, because this change should be done here. They provide little BC-break.

Closes #1871.

Changelog

### Changed
- Change using `Sonata\Doctrine\Model\PageableManagerInterface` in favor of `Sonata\DatagridBundle\Pager\PageableInterface`
### Removed
- Removed support for `sonata-project/datagrid-bundle` < 3.0

[VincentLanglet]

Can you explain why the typehint are added/needed ?

[wbloszyk]

Can you explain why the typehint are added/needed ?

Becouse *Managers are implementing Sonata\Doctrine\Model\PageableManagerInterface for pager which is deprecated in favor of Sonata\DatagridBundle\Pager\PageableInterface. In DatagridBundle 2.x all will be work. BC-break is present to allow bump DatagridBundle to v3. Otherwise update some sonata bundles will be impossible. (This which currently support only DatagridBundle v3).

[VincentLanglet]

sonata-project/datagrid-bundle: ^3 was already allowed by the composer.json.
Do you mean it was not possible to install it ?

[wbloszyk]

sonata-project/datagrid-bundle: ^3 was already allowed by the composer.json.
Do you mean it was not possible to install it ?

Sonata\Doctrine\Model\PageableManagerInterface::getPager() will allow for both DatagridBundle version (^2.0 || ^3.0)
Sonata\DatagridBundle\Pager\PageableInterface::getPager() is without type hints is in 2.x
Sonata\DatagridBundle\Pager\PageableInterface::getPager() is with type hints is in 3.x

When we change using Sonata\Doctrine\Model\PageableManagerInterface in favor of Sonata\DatagridBundle\Pager\PageableInterface we have to drop support for DatagridBundle 2.x.

[phansys]

IMO, breaking the signature of public methods is considered a BC break.
Is there a strong reason to introduce this break in 3.x?

[wbloszyk]

IMO, breaking the signature of public methods is considered a BC break.
Is there a strong reason to introduce this break in 3.x?

Probably of overriding these mehods are very low. I want to reduce deprecation. I can also move this PR to master and do not display deprecations if people do not override it.

[VincentLanglet]

If this is a blocking point for some needed support/fixing something. We could think about it.
If this is only for a deprecation it would be better on master indeed.

[wbloszyk]

Close in favor of #1925