Revert "Remove old-style event tags."

Reverts saltstack/salt#17235

@cachedout @thatch45 This commit introduced some test failures, so I am reverting this for now until they can be cleaned up. The original PR test data isn't available any more, so if you're wondering, the relevant failures were:
- integration.client.kwarg.StdTest.test_full_returns
- integration.client.kwarg.StdTest.test_kwarg_type
- integration.client.standard.StdTest.test_full_returns
- integration.shell.matcher.MatchTest.test_static