Revise DigitizationTestsMT ART jobs
This merge request tidies the syntax of the MC15-style tests and adds matching tests for MC16a-style digitization. It also adds tests which compare AthenaMT to Athena output for certain sub-systems.
This merge request tidies the syntax of the MC15-style tests and adds matching tests for MC16a-style digitization. It also adds tests which compare AthenaMT to Athena output for certain sub-systems.