PersistReco serialisation functionality

Add PersistReco serialisation functionality as described in #204 (closed) and lhcb-dpa/project#15, based on developments in !628 (merged) and !646 (merged). To be specific:

1. Add the serialisation step to Moore, including rewriting the locations to these in PersistRecoConf.
2. Add the deserialisation to the various output-checking tests.
3. Re-enable the Hlt2Conf.test_persistreco_output_realtime test.
4. Create a new version of the existing Hlt2Conf.test_hlt2_check_output for real-time reco, which reads the output of Hlt2Conf.test_hlt2_all_lines_with_reco.

The (de-) serialisation of PackedWeightedRelations-type containers, i.e. PP2MCPRelations, needs the patch in LHCb!2862 (merged).

To traverse the data flow tree for all kinds of inputs requires the patch LHCb!2911 (merged).

The location related to MuonID is hard-coded for now. The issue is traced in #242.

The serialisation of raw event (input type of MDF) uses event store of HiveWhiteBoard instead of EvtStoreSvc as a workaround. The issue is tracked by gaudi/Gaudi#162 and LHCb!2878 (merged).

Tests with mixed reco and fromfile configuration (*reco_mix*.qmt) are disabled, as they are not supported by PersistReco configuration, see #234 (closed)

Depends on LHCb!2926 (merged)