Fix simulation of SemiVisible Jet samples and additional debugging output for SUSY/Exotics simulation tests

John Derek Chapman requested to merge jchapman/athena:SUSYExotics_QS_21.0 into 21.0

As part of the debugging of SemiVisible Jet simulation (ATLMCPROD-10058) it was found that simulation of SUSY/Exotics samples where G4 physics is extended and quasi-stable particle simulation is enabled does not work correctly in 21.0. This is the same issue that I recently fixed in 22.0. I will back-port the fixes in a follow-up MR, but this initial merge request updates the ART tests, so that they can spot the problem and so should flag up when it is fixed.

It also adds some fixes that should allow the simulation of SemiVisible Jet samples to proceed correctly in the future.

FYI @jmaurer, @biliu.

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