online: Adding auxiliary digi data to STS digi QA

• The auxiliary data objects from unpackers are stored in a temporary data structure AuxDigiUnpack (TODO: Dummy classes for DigiQa, execute the QA inside the Reco::RunUnpacker function)
• The option "--aux-data" is added to force saving the auxiliary data in unpackers (now is used only by sts::Unpack)
• STS digi QA: histograms for channel vs. e-link are added for different modules