Clustering should be able to accurately handle passivation/handoff(rebalance)

[briansain]

Version Information
Version of Akkatecture?
Akkatecture.Cluster

Describe the bug
The framework does not handle passivation and handoff messages well. The default behaviour for Akka.Net is to send a PosionPill during passivation/handoff (rebalance). Since there are layers to the aggregates/entities, the shard actor doesn't get notification of complete passivation/handoff which leads to an instable state.

Expected behavior
If a shard wants to passivate an idle entity or rebalance a shard, then the shard to be aware of when the process is completed on that aggregate(s).

Actual behavior
Aggregates are passivating, but the stashed state of the entity within the actor shard remains in the passivating state.

Environment
Docker

[malclear]

I'll look at this this coming week, Brian. If you'd like to and have time to talk about it, reach out through Discord.