Saving SCT hits in .h5 produced by TDD for the flavour jet tagging with Hits

The main motivation for this marge request is to be able to save hits from SCT inside the TDD output.h5.

• To do this, processSingleBTagEvent.cxx was modified by introducing the decorator isSCT (true if the hit comes from SCT false otherwise). This is because we realised that certain variables are present in decorating hits in Pixels but not in those in SCTs.

• In HitWriter.cxx we have therefore changed the way decorator variables that are not in common between SCTs and Pixels (e.g. isFake) are saved. When the hit is from pixel, the value from AOD is stored in the variable, whereas when the hit is from SCT, the variable stores a -1.

• Finally, a configuration variable was created inside the json file EMPFlow.json: save_sct was added inside the hits dictionary, which saves hits from SCT in case this variable is true.