Persist user/password info for nodes

[knolleary]

@louison

hit deploy and the credentials get saved. I don't know where ? Probably in RAM but not in flows.json

When you deploy the MQTT Broker node, its credentials are stored in the credentials file. That is where all node credentials are stored.

As I said before, I'm not aware of a node that can dynamically store values like credentials in a secure manner.

You could store them in context, but that would require persistent context to be enabled, and the credentials would be stored unencrypted.