This adds a feature to moz-http2's doh path that helps test connection cycling. We log the remote ports of DoH requests and expose an API to fetch the log. A specific name will trigger us to send a delayed response to help simulate network volatility. The log is then checked for correctness in the test script. Differential Revision: https://phabricator.services.mozilla.com/D131467
Common testing tools for mozilla codebase projects, test suite definitions for automated test runs, tests that don't fit anywhere else, and other fun stuff