Function deltachat::chat::add_device_msg_with_importance

pub async fn add_device_msg_with_importance(
    context: &Context,
    label: Option<&str>,
    msg: Option<&mut Message>,
    important: bool
) -> Result<MsgId>

Adds a message to device chat.

Optional label can be provided to ensure that message is added only once. If important is true, a notification will be sent.