Add ITS fake clusters information to the mcMask

[fmazzasc]

BITS 0-6 were not set, in contrary to what was stated in the mcMask description in AnalysisDataModel.h .
I also added a bit to account for fake AB ITS tracklets (BIT 12) and fixed the description of the last three bits inAnalysisDataModel.h

Could you please have a look?
@shahor02 @jgrosseo @ddobrigk

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[shahor02]

Thanks, just 1 comment below.

[shahor02]

This check is not needed, if trackIndex.includesDet(DetID::ITS) is true, then the itsGID.isIndexSet() is guaranteed.
Just check

if (itsGID.getSource() == GIndex::ITS) { 
 ... as ITS track
} else {
 ... as AB track
}

[fmazzasc]

Thank you ! Fixed

[alibuild]

Error while checking build/O2/fullCI_slc9 for 4ae732a at 2025-09-16 13:38:

No log files found

Full log here.

[f3sch]

Hi @shahor02, can we merge this if it looks good, thanks.