Follow-up from "Adding missing features for correctly reading a spruced file"

Follow up from !577 (merged) to be addressed:

• create an integration test for the HLT1->HLT2->Sprucing->DaVinci chain (see !577 (comment 4934950))
• create a wrapper/function to return a list of all the filters and tupling algorithms added to the control flow (see !577 (comment 4941169)).

Related to DPA grand task https://gitlab.cern.ch/lhcb-dpa/project/-/issues/48.