[FEATURE REQUEST] support kafka set SASL Mechanism

[John-Funcity]

Why this feature?

aws msk 的SASL/SCRAM 身份验证 认证方式，需要设置SASL设置为SCRAM-SHA-512，可否在config增加该配置项？

Suggested Solution

在sarama.go中增加

       if conf.Username != "" || conf.Password != "" {
		kfk.Net.SASL.Enable = true
		kfk.Net.SASL.User = conf.Username
		kfk.Net.SASL.Password = conf.Password
                # 增加
                kfk.Net.SASL.Mechanism = conf.Mechanism
	}

Additional Information

No response