Regression tests should be refactored as Au and Catch tests

[ywkaras]

That is, the regression tests run with the -R option on the traffic_server command.

There seems to be consensus that these tests are hard to maintain.

Related issues:
#5048
#2637
#1587
#5049

[ywkaras]

In some cases, regression tests run in separate unit test executables (built and run by 'make check'). This PR converts one such executable to Catch tests: https://github.com/apache/trafficserver/pull/6544/files .

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.