Summary: Starting to look into a DNS protocol parser. Start with an existing simple parser.

Test Plan: None

Reviewers: yzhao, #engineering, zasgar

Reviewed By: #engineering, zasgar

Differential Revision: https://phab.corp.pixielabs.ai/D6436

GitOrigin-RevId: 9ef66a042b168bc1f48f248a45b9d658560b64af