Adding a new user

[shadowofleaf96]

• Add a new user

Rules

1. Only users with admin role can create new users.
2. The user's account is active by default and set to true.
3. The user username should be unique.
4. The user email should be unique.
5. A notification email is sent to the user with his credentials.
6. The creation date data should be set when creating a new user.