getMCShowerType fails on Sh_228

[mdhank]

The getMCShowerType function (https://github.com/UCATLAS/xAODAnaHelpers/blob/main/Root/HelperFunctions.cxx#L520) doesn't cover all samples. In particular, the sample mc20_13TeV:mc20_13TeV.700000.Sh_228_ttW.deriv.DAOD_PHYS.e7793_s3681_r13167_p5631
(corresponding to Sherpa 2.2.8p3) returns an Unknown. This cases processing to fail in https://github.com/UCATLAS/xAODAnaHelpers/blob/main/Root/BJetEfficiencyCorrector.cxx#L245 .

Should Sherpa 2.2.8p3 return case HelperFunctions::Sherpa22? If so, I can make an MR for this.

[mdhank]

It turns out this is not supported by FTAG, but our calibrations lists are out of date: https://ftag.docs.cern.ch/algorithms/activities/mcmc/#list-of-supported-generators-with-reference-dsid