Add batch_size to qdrant __init__

[pandasar13]

Is your feature request related to a problem? Please describe. I am using various document stores and notice some differences in the init. For instance while Opensearch, Weaviate or Elasticsearch allow to specify the batch_size in the init method. Qdrant does not allow it. I know that it can be changed later when using write_documents but if someone wants to use a pipeline it is not so straight-forward to change the batch size.

Describe the solution you'd like

Add batch_size to the init of qdrant.

I could open a PR if you agree