[SECURITY]: Store Password as Salted Hash

[explocion]

Is your feature request related to a problem? Please describe.
Store the password as salted hash instead of plantext in the database.

Describe the solution you'd like
Modify the database model User so that it has 3 fields: username, salt, and salted password hash using a safe password hashing algorithm (e.g. Argon2id). The authentication process is fetch the salt and salted hash using the username, compute the hash again using user password input, and finally compare whether the hashes match.

Describe alternatives you've considered
N/A.

Additional context
Go Argon2