Add support for dual passwords

Hello MariaDB Team,

I couldn't find an already opened issue or discussion to implement dual passwords in MariaDB.

MaxScale supports it: https://jira.mariadb.org/browse/MXS-4232
ProxySQL supports it: https://proxysql.com/documentation/password-management/#dual-passwords-v30
MySQL 8.0 supports it: https://dev.mysql.com/doc/refman/8.0/en/password-management.html#dual-passwords

Is it possible to implement it in MariaDB?

Thanks & Cheers,
Joffrey