support MD5 and SCRAM-SHA-256 auth for better security?

[rich-c-shop]

Background

ClearTextPassword is supported.
https://github.com/jeroenrinzema/psql-wire/blob/v0.12.2/auth.go#L48

Expect

MD5 and SCRAM-SHA-256 are supported
https://www.postgresql.org/docs/current/auth-password.html

[jeroenrinzema]

Hi @rich-c-shop, thanks for opening a issue! I am planning to support the SCRAM-SHA-256 protocol but did not have the time yet to implement it.