Enable BLS slice in RDOtoRDOtrigger transform
Second attempt to merge the changes from !26278 (closed).
This MR adds BLS slice to RDOtoRDOtrigger transformation, to have them in TrigAnalysisTest. Addresses ATR-20241. As a test I ran the TrigAnalysisTest, the output is in /afs/cern.ch/work/t/tursom/public/test_trigAna_q221_RDOtoAOD_mt1_build.tar.gz; the changed reference in Trigger/TrigValidation/TrigAnalysisTest/share/q221_RDOtoRDOTrig_mt1_build.ref is also updated.