Adapt decay descriptor tests to new ion names
Update test of the decay descriptors to use the new ion names without the additional [0.0]
for ground states, so e.g. He3
instead of He3[0.0]
. These changes were introduced to the ParticleTable in DDDB in lhcb-conddb/DDDB!131 (merged) and are to be ported to LHCb in LHCb!4579 (merged).