Check DKIM Authentication-Results (#3583)

Fix #3507

Note that this is not intended for a release at this point! We first have to test whether it runs stable enough. If we want to make a release while we are not confident enough in authres-checking, then we have to disable it.

BTW, most of the 3000 new lines are in `test_data/messages/dkimchecks...`, not the actual code

da3a4b94 adds the results to the Message info. It currently does this by adding them to `hop_info`. Maybe we should rename `hop_info` to `extra_info` or something; this has the disadvantage that we can't rename the sql column name though.

Follow-ups for this could be:
- In `update_authservid_candidates()`: Implement the rest of the algorithm @hpk42 and me thought about. What's missing is remembering how sure we are that these are the right authserv-ids. Esp., when receiving a message sent from another account at the same domain, we can be quite sure that the authserv-ids in there are the ones of our email server. This will make authres-checking work with buzon.uy, disroot.org, yandex.ru, mailo.com, and riseup.net.
- Think about how we present this to the user - e.g. currently the only change is that we don't accept key changes, which will mean that the small lock on the message is not shown.
- And it will mean that we can fully enable AEAP, after revisiting the security implications of this, and assuming everyone (esp. @link2xt who pointed out the problems in the first place) feels comfortable with it.

src/chat.rs

@@ -3702,11 +3702,11 @@ mod tests {
 
         // create group and sync it to the second device
         let a1_chat_id = create_group_chat(&a1, ProtectionStatus::Unprotected, "foo").await?;
-        a1.send_text(a1_chat_id, "ho!").await;
+        let sent = a1.send_text(a1_chat_id, "ho!").await;
         let a1_msg = a1.get_last_msg().await;
         let a1_chat = Chat::load_from_db(&a1, a1_chat_id).await?;
 
-        let a2_msg = a2.recv_msg(&a1.pop_sent_msg().await).await;
+        let a2_msg = a2.recv_msg(&sent).await;
         let a2_chat_id = a2_msg.chat_id;
         let a2_chat = Chat::load_from_db(&a2, a2_chat_id).await?;