Enable JID stringprep feature in higher-level crates
Now that stringprep support in jid crate does not panic anymore, should we not enable it by default in higher-level crates? Or at least in xmpp-rs.
NOTE: Need to update the CHANGELOG for jid which says stringprep errors return JidParseError::IcuError
, while it now returns (since 4701f6bb) a JidParseError::Stringprep
.