Add test count checking to UnitTestGroup

[Sqeaky]

Each Test group needs to provide a count of the expected amount of tests. This should be checked after the tests are run to determine if they all ran. This will help prevent certain kinds of logic errors in the tests and prevent tests that launch sub processes from crashing and skipping post crash tests without being noticed.

This should add another TestData to the Main collection with name indicating it is a count and should correctly indicate failure or success.