Add more control over on the user creation for users that doesn't already exist in the users collection

[yaronuliel]

When a user pass the authentication level, while it doesn't exist in the users collection - currently the plugin creates a new user in the collection without much control (aside from the collection config)

It would be great if we could completely disable the missing user create via plugin config (sometimes authorization is fully managed inside the app, while only the authentication step is manages in the external identity provider).

Also, it would make sense to be able to pass a callback function that receives the JWTUser object and returns the properties of the new user to create (while returning null means - don't create user or something like that)

[WilsonLe]

Also, it would make sense to be able to pass a callback function that receives the JWTUser object and returns the properties of the new user to create (while returning null means - don't create user or something like that)

Maybe I misunderstood but isn't that's what the configurable getUserInfo does?