Turn NeoChatConnection::isVerifiedSession into a notifiable property

This should allow the devices page to hide the "Verify this Device"
warning, once you actually complete verification. I also made sure to
update the other consumer - the menu item under the user menu.

Additionally, I also fixed the password field not being automatically
focused when trying to remove a device.

src/libneochat/neochatconnection.cpp

@@ -141,6 +141,12 @@ void NeoChatConnection::connectSignals()
             });
         },
         Qt::SingleShotConnection);
+
+    connect(this, &Connection::sessionVerified, this, [this](const QString &userId, const QString &deviceId) {
+        if (userId == this->userId() && deviceId == this->deviceId()) {
+            Q_EMIT ownSessionVerified();
+        }
+    });
 }
 
 int NeoChatConnection::badgeNotificationCount() const