Function send_chat_request_and_parse_stream 

pub async fn send_chat_request_and_parse_stream(
    pool: PgPool,
    app_configuration: &ApplicationConfiguration,
    chatbot_configuration_id: Uuid,
    conversation_id: Uuid,
    message: &str,
    page_context: Option<ChatbotPageContext>,
    user_context: ChatbotTurnContext,
) -> ChatbotResult<Pin<Box<dyn Stream<Item = ChatbotResult<Bytes>> + Send>>>

Starts a turn for a new user message, and streams its NDJSON events to the client.