fix!: Download outgoing messages only from Sentbox and if SentboxWatch is set (#7169)

Download outgoing messages only from Inbox and Mvbox (and Sent -- until `Config::SentboxWatch` is
dropped) to ensure they are sorted correctly with incoming messages. This way we actually do
server-side sorting. Otherwise it's possible that outgoing replies from other devices appear before
incoming messages. Users should CC/BCC/To themselves to see sent messages in Delta Chat.

src/scheduler.rs

@@ -661,6 +661,7 @@ async fn fetch_idle(
 
     connection.connectivity.set_idle(ctx);
 
+    // Maybe we'll remove watching other folders soon, so use this event for all folders for now.
     ctx.emit_event(EventType::ImapInboxIdle);
 
     if !session.can_idle() {