* add draft of WriteToStore and basic test
* add DocumentWriter implementation
* draft unit and integration tests
* add release note
* mock Store in unit tests
* pylint
* Update haystack/preview/components/writers/document_writer.py
Co-authored-by: Daria Fokina <daria.fokina@deepset.ai>
* Remove unnecessary test
* Rework DocumentWriter to support new Component I/O definition
---------
Co-authored-by: Daria Fokina <daria.fokina@deepset.ai>
Co-authored-by: Silvano Cerza <silvanocerza@gmail.com>
