Add readOne() method in the DataReaderInterface

[roxblnfk]

I suggest adding a method for reading a single element in the DataReaderInterface.
This method will work in much the same way as the read() method with a limit of 1, but will return not the collection of elements, but the first element.

interface DataReaderInterface
{
    public const DEFAULT_LIMIT = 10;

    public function withLimit(int $limit);
    public function read(): iterable;
    public function readOne();
}

[samdark]

I am fine with having it.