IBX-8394: Created Rector to rename RepositoryConfigurationProvider usages

[alongosz]

🎫 Issue	IBX-8394

Description:

Added to Ibexa 5.0 set list a rule which renames usages of deprecated \Ibexa\Bundle\Core\ApiLoader\RepositoryConfigurationProvider with
\Ibexa\Contracts\Core\Container\ApiLoader\RepositoryConfigurationProviderInterface

Added also test coverage for the Ibexa 5.0 set - can be in the future expaned with coverage for pre-existing and new configuration.

DX: Defined \Ibexa\Contracts\Rector\Sets\IbexaSetList set list, so the Developer's rector.php config could be as follows:

   
declare(strict_types=1);

use Ibexa\Contracts\Rector\Sets\IbexaSetList;
use Rector\Config\RectorConfig;

return RectorConfig::configure()
                   ->withPaths([__DIR__ . '/src', __DIR__ . '/tests'])
                   ->withSets([IbexaSetList::IBEXA_50->value])
;

instead of hardcoded path from ./vendor/....

For QA:

Documentation:

Changed example configuration.

[alongosz]

Note: Rector per design expects that a Developer runs CS fixer afterwards. For the automated PR I'll run CS fixer with extra FQCN import rule, which will both remove unused use and simplify FQCN.

[alongosz]

Update: aligned docs with the changes.