Support enable passwords

Currently, all drivers use the login password as the enable password.
This is not desirable in all scenarios, since we dont support separate enable passwords.

To support it in a proper way, there should be a list of enable passwords in credentials screen, and which is used for which device would be automatically discovered during device discovery.

This will need changes to the wizard, the credentials screen, the discovery process (to detect which of a list of enable passwords are correct), and changes to all drivers that require entering enabled mode (not to mention rewriting all the related code and tests).