Function open_quote_now 

fn open_quote_now(
    qt: &CxxQtThread<Sioul>,
    shared: &Arc<Shared>,
    draft: &Draft,
    ident: &str,
    typed: Option<Password>,
)

Opens the encrypted message a draft answers with the security key ident, another than the one that signs: its session key is kept in memory, and the draft goes on to its signature, whose key asks its own PIN.