Immediately display connect errors in the login page

This is using a Kirigami.InlineMessage component.

src/controller.h

@@ -88,7 +88,11 @@ private Q_SLOTS:
 
 Q_SIGNALS:
     void busyChanged();
+    /// Error occured because of user inputs
     void errorOccured(QString error, QString detail);
+
+    /// Error occured because of server or bug in NeoChat
+    void globalErrorOccured(QString error, QString detail);
     void syncDone();
     void connectionAdded(Quotient::Connection *conn);
     void connectionDropped(Quotient::Connection *conn);