User password creation strategy

For now, the current user creation strategy in our new user management is based on Okta behaviors.
=> no password is set then follows Okta invitation process, and password definition. There is no password set in the `userDirectory`.

On an onprem deployment, Okta is not mandatory and we need to define a strategy that lets the user logon after being added to an organization.

One approach could be to listen on `userCreated` w/o a password and set it + send an email to warn the user.
Open to discussion.