tests/phpunit - Flag 3 ornery test classes

tests/phpunit - Flag 3 ornery test classes

At the moment, a handful of tests in `CRM_AllTests` are failing (for
different reasons).  This creates a bind:

 * If we run `CRM_AllTests` as part of PR testing, then it will
   cause lots of annoyance and train people to disregard test outputs.
 * If we don't run `CRM_AllTests` as part of PR testing, then we're
   liable to get more regressions spotted too late.
 * Some of the failures don't appear to be trivial to resolve.

The idea here is to flag these particular tests as `ornery`.  For PRs, we'll
enable tests with `CRM_AllTests` but also `--exclude-group ornery`.