Parse input sent via XMLConsole

This allows us to show the user an error if the stanza is invalid.
Until now the server would instantly disconnect us.

Also this fixes the problem that XMLConsole input was not counted for
streammanagement.

Fixes #8563

gajim/dialogs.py

@@ -3503,7 +3503,14 @@ class XMLConsoleWindow(Gtk.Window):
         begin_iter, end_iter = buffer_.get_bounds()
         stanza = buffer_.get_text(begin_iter, end_iter, True)
         if stanza:
-            app.connections[self.account].send_stanza(stanza)
+            try:
+                node = nbxmpp.Protocol(node=stanza)
+                if node.getNamespace() == 'http://www.gajim.org/xmlns/undeclared':
+                    node.setNamespace(nbxmpp.NS_CLIENT)
+            except Exception as error:
+                ErrorDialog(_('Invalid Node'), str(error))
+                return
+            app.connections[self.account].connection.send(node)
             buffer_.set_text('')
 
     def on_input(self, button, *args):