add `delete_all_documents()` operation to `QdrantDocumentStore`

[davidsbatista]

• One possible solutions is to delete the collection holding all the documents and recreate it with the original configuraiton

client.delete_collection(collection_name=collection_name)

client.create_collection(
    collection_name=collection_name,
    vectors_config={
        "size": 768,  
        "distance": "Cosine"
    },
)

• Another is to delete all points/documents using a wildcard filter

client.delete(
    collection_name=collection_name,
    points_selector=models.FilterSelector(
       filter=models.Filter(
           must=[  # Match all points (adjust if you have specific conditions)
               models.FieldCondition(
                   key="id",  # Assuming 'id' is a payload field; adjust if needed
                   match=models.MatchValue(value="*"),  # Wildcard (may not work for all field types)
                   )
                   ])),)