Visualize if config is read from file instead of from node

[espen42]

Request for GUI update in response to new feature that allows an ID provider to be configured from .cfg file instead of from settings stored in node layer.

Should be able to detect and visualize it if the file is used instead of from node layer, eg. disable/grey out all fields in the config (keep the values from .cfg hidden for security reasons)...

...or just disable the edit button.

Detection should not be based on something in the node layer, but probably whether or not the config file exists/is used by the idprovider app.

[espen42]

Possibly use a field in the userstore config at node level: cfgFile. If not preset, it defaults to false. If the .cfg file is present, it's set to true and the config fields in the user admin app can visualize it.