Make CaloFutureElectron tool thread safe

This MR is connected to LHCb!2239 (merged) and refers to issue #106
Main changes are in CaloFuture/CaloFutureTools/src/CaloFutureElectron.cpp
all callers accept now a protoParticle and inside call set if necessary.
set returns a pair of LHCb::CaloHypo* (electronHypo, bremstrahlungHypo)
set is left public and called from outside to keep the logic unchanged especially when a counter depends on successful set.