chg: [eventGraph] better support of hidden event (possibility to show hidden item back latter on)
chg: [eventGraph] better support of hidden event (possibility to show
hidden item back latter on)

MISP/MISP,SteveClement/MISP,FIRSTdotorg/MISP,FIRSTdotorg/MISP,Rafiot/MISP,Rafiot/MISP,MISP/MISP,FloatingGhost/MISP,devnull-/MISP,MISP/MISP,FIRSTdotorg/MISP,SteveClement/MISP,MISP/MISP,devnull-/MISP,SteveClement/MISP,MISP/MISP,FloatingGhost/MISP,FloatingGhost/MISP,Rafiot/MISP,devnull-/MISP,devnull-/MISP,SteveClement/MISP,FloatingGhost/MISP,Rafiot/MISP,SteveClement/MISP,FIRSTdotorg/MISP