Improve LifetimeDefinition to support single handle w/out arrays creation

[sidristij]

in fact we could optimize footprint even better by changing object[] to object for single object

[sidristij]

I can try to implement this task.

[korifey]

Hi @sidristij. It's a great thought. Lifetime used to have at least 2 children (1 as parent reference) so we didn't need such an optimization. But maybe it's not the case now.