support reading passwords using org.freedesktop.secrets spec (a.k.a, from keyring)

[Avinash-Bhat]

(Storing passwords in plain text may not be a good idea.)

It would be quite easier if the app reads from the keyring (https://www.freedesktop.org/wiki/Specifications/secret-storage-spec/) using config like:

[servers.liberachat.sasl.plain]
username = "foobar"
use_keyring = true

If the keyring doesn't have the password, then the password can be taken from the user and stored in the keyring.

crate libsecret can be used for this purpose