Restructure the Add User states so that validation is performed as close as possible to data entry.

The add user utility now has support for asking for numerous fields, however validation often occurs late, this introduces a few problems: -
1 - Inconsistent logic after errors as sometimes subsequent validation is skipped.
2 - Users entering a lot of values for the process to begin again.

This change is to validate each value as soon as it is entered and also to reduce some of the overloading that seems to have been added to each state e.g. a state to prompt for a password should not be prompting for the users roles.