[NodeAnalyzer] Detect Doctrine static function mapping (loadMetadata) entity in DoctrineEntityDetector

[TomasVotruba]

Recognize Doctrine static function mapping classes as entities in DoctrineEntityDetector.

Such classes map their fields in a loadMetadata() method instead of attributes/annotations, so the existing annotation + attribute detection misses them. The detector now also treats a class defining a loadMetadata() method as a Doctrine entity. The cheap, pure-AST check runs first.

Example

use Doctrine\ORM\Mapping\ClassMetadata;

final class Product
{
    private $name;

    public static function loadMetadata(ClassMetadata $metadata): void
    {
        $metadata->mapField([
            'fieldName' => 'name',
            'type' => 'string',
        ]);
    }
}

Product is a Doctrine entity even without any annotation or attribute, so DoctrineEntityDetector::detect() now returns true for it.

Mirrors rectorphp/rector-src#8059, which skips such classes in TypedPropertyFromAssignsRector and RemoveUnusedPrivatePropertyRector.