[feature] Add Tome to Add Users/Set Passwords

[jabbate19]

Is your feature request related to a problem? Please describe.
When I have to reset a password, I have to run a shell command like printf("password\npassword\n") | passwd to get the result I want.

Describe the solution you'd like
A tome that provided a username/password, can ensure the user exists and set the password.

Describe alternatives you've considered
Writing to /etc/passwd and /etc/shadow directly

Additional context
FreeBSD's /etc/shadow equivalent is /etc/master.passwd