Add zero-suppressed HltDecReport rawbank format

In case the list of known decisions for the decoding key which encodes them is equal to (and not eg. a superset of) the list of decisions actually present in a decreport, and the relevant property is set, store a zero-suppressed HltDecReport raw bank, i.e. skip those decisions which are equal to a default-constructed DecReport with only its ID set. When a zero-suppressed bank is decoded, first decode the bank, and then loop over the table corresponding to the decoding key of the bank, and add all entries which are not yet present by default constructing the decision, and setting their ID.