Add UnpackDstDataBank which unpacks the entire DstData raw bank

Add UnpackDstDataBank, an algorithm that 'just' unpacks everything in the DstData raw bank and repopulates the event store -- it does not provide data handles which could be used during configuration, as the data it produces is fully determined by the content of the DstData bank it encounters... so while fully deterministic, it is not a-priori predictable without inspecting the data. But it can be useful in GaudiPython scripts which want to explore the event store, and eg. validate the content of the DstData raw bank.