Sending a new cluster config properly when a folder state changes

Hello Syncthing Team,

I am working on an issue about announcing folder states to a remote device and I have previously created this draft PR but I was not able to send the cluster config properly.

Now in this branch that I am working on I believe that I am sending the cluster config properly although I am not receiving it. Is there a different function to send the config other than sendClusterConfig?

Thank you!