feature-request: SASL SCRAM Mechanism

[Andrew-Chen-Wang]

Hi I'm fairly new to the repo, and I liked the article originally published for this.

I was wondering how difficult it would be to implement the SCRAM SASL mechanisms as I'm fairly new to the repository, but Redpanda cloud requires it.

[crepererum]

A while back SASL plain was implemented (#216). The code from that PR probably needs to be extended for SCRAM. PRs are welcome.

[crepererum]

Closed by #247.