Decouple MetaData configuration for DAODs
This is yet another follow-up to !61368 (merged). With this MR, each DAOD format now configures its own MetaData instead of doing this in the main skeleton (just like EventData but not quite as flexible yet, which needs a more modular InfileMetaDataCfg but that's another story). It also fixes the bug reported w/ the DAOD_TRUTHX production jobs.
Closes ATLASG-2496