Remember user's last entered Auth Factor

Feature: Remember user’s last entered Auth Factor

Description: For an optimal user experience, we would like to have the capability to remember the user’s last known auth factor. If the user last used email+password, we would like to dynamically switch the Auth screen to show email+password and still include a link to one-time code if the user elects. This should not block the user from selecting Social SSO on the primary identifier screen, meaning the UX should still remain flexible but we are allowing a shorter path for the user to auth in to their account or desired experience.

Use-case: covered in the description above.