SLB: Application of the relation table algorithm to store MVA score

Application of Rec!4126 to SL sprucing lines

Needs LHCb!4872

Changes in BW in different configurations (evaluated on 10k minbias sample):

persistency	BW (GB/s)
extra tracks duplicated (current version)	0.181
extra tracks not duplicated	0.180
B relation table + extra tracks not duplicated
B relation table + B^{\star} relation table + extra tracks not duplicated

Current status

The current MR removes the duplicates from the Selection of particles from the rest of the event persisted during the sprucing. Adding the relation table between signal candidates and particles from the rest of the event, weighted by the MVA score, makes the test failing with the following error.

LHCb__SelectivePacker_cd1c82bb        ERROR bool LHCb::{anonymous}::{anonymous}::Item<KeyedContainer<ValueType, Mapping> >::emplace(const ValueType*) [with ValueType = LHCb::Particle; Mapping = Containers::KeyedObjectManager<Containers::hashmap>] : attempt to add to locked item (potential circular dependency?)
LHCb__SelectivePacker_cd1c82bb        ERROR Maximum number of errors ( 'ErrorMax':1) reached.
HLTControlFlowMgr                     FATAL Event failed in Node HltPackedBufferWriter/HltPackedBufferWriter_97f7c229
HLTControlFlowMgr                      INFO Application return code set to 3
HLTControlFlowMgr                     FATAL Event 861 on slot 0 failed!
HLTControlFlowMgr                     FATAL *** Too many consecutive failures 1, stopping now ***

Full log: log.txt

FYI: @graven, @sstahl, @mveghel, @decianm, @mfontana, @nskidmor