Add a passwod confirmation field to the create admin form

[madneutrino]

The admin account signup page currently takes in Name, email and password.

However, there is no account reset mechanism (except re-initializing the whole server). So a typo in the email or password (but more likely in the password since it is hidden) would break the onboarding flow. Adding a password confirmation field would somewhat mitigate this and ease the onboarding process.