feat: get contact-id for info messages (#6714)

instead of showing addresses in info message, provide an API to get the
contact-id.

UI can then make the info message tappable and open the contact profile
in scope

the corresponding iOS PR - incl. **screencast** - is at
https://github.com/deltachat/deltachat-ios/pull/2652 ; jsonrpc can come
in a subsequent PR when things are settled on android/ios

the number of parameters in `add_info_msg_with_cmd` gets bigger and
bigger, however, i did not want to refactor this in this PR. it is also
not really adding complexity



closes #6702

---------

Co-authored-by: link2xt <link2xt@testrun.org>
Co-authored-by: Hocuri <hocuri@gmx.de>

src/sync.rs

@@ -743,10 +743,7 @@ mod tests {
         let fiona = &tcm.fiona().await;
         tcm.exec_securejoin_qr(fiona, alice2, &qr).await;
         let msg = fiona.get_last_msg().await;
-        assert_eq!(
-            msg.text,
-            "Member Me (fiona@example.net) added by alice@example.org."
-        );
+        assert_eq!(msg.text, "Member Me added by alice@example.org.");
         Ok(())
     }
 }