Explicitly enable email notification when user account is set to "login denied"

When setting the user account state to "login denied" to temporarily block users, users will get an email notification. However, the user manager who triggered this change is not aware that this email will be sent not is he informed after the change that the email was sent.

Im praxis, this leads to confusing users wo respond to the email, often they don't even recall they used the system several month ago for some tasks.

The goal is to make this email notification optional and not enabled by default.

The changes are in the roles configuration panel in the usermanagement of a single user and also in the user bulk change workflow.