Function delete_message 

pub async fn delete_message(
    configuration: &Configuration,
    room_name: &str,
    serial: &str,
    x_ably_version: Option<&str>,
    idempotency_key: Option<&str>,
    delete_message_request: Option<DeleteMessageRequest>,
) -> Result<Message, Error<DeleteMessageError>>

Soft-deletes a message. This is a POST to a /delete sub-resource (not an HTTP DELETE). Produces a new message version with action message.delete; the deleted message remains retrievable with its delete action applied.