Add user auth support for zabbix-agent2 redis plugin

Redis since 6 version, supports user ACL (ACL user password), go-redis also supports Options.Username parameter in connection options since v7.3.

But redis plugin documentation said

"Embedded URI credentials (userinfo) are forbidden and will be ignored. So, you can't pass the credentials by this:

redis.ping[tcp://user:[email protected]] — WRONG"

I wonder, why. Using ACL like "user zabbix on [email protected] +info +config +slowlog >password" and connection URI tcp://zabbix:[email protected]:6379 is more configurable and secure way, than using global admin password for all redis instances.