feat: do not show the address in invite QR code SVG

Addresses take space and sometimes
do not fit. We generally want
to deemphasize addresses in the UI,
especially randomized chatmail
addresses.

src/stock_str.rs

@@ -859,10 +859,10 @@ pub(crate) async fn setup_contact_qr_description(
     display_name: &str,
     addr: &str,
 ) -> String {
-    let name = if display_name == addr {
+    let name = if display_name.is_empty() {
         addr.to_owned()
     } else {
-        format!("{display_name} ({addr})")
+        display_name.to_owned()
     };
     translated(context, StockMessage::SetupContactQRDescription)
         .await