Argon2id hashed passwords in userdb

[zungur]

This (darft) PR assumes that all the passwords are hashed in the DB Will provide a script for this later on

• User Argon2id for password hashing
• Cache hash comparison result of least recent auths
• Register new users with hashed passwords in userdb
• ~~Hash existing passwords on first authentication~~
• Remove password output to stdout/stderr
• New error message when username is not registered
• Order of auth errors are preserved (i.e., wrong pwd > blocked > pending)
• New unit tests