Inject shared state IDs computed in StateAssignmentOperation (FLINK-23342) into the SharedStateRegistry and CheckpointsCleaner and ignore other states. Should only affect changelog states (both materialized and non-materialized).
Injection into SharedStateRegistry is done in FLINK-23342 (or can be done in this ticket).
Should take "changelog.enabled" and it's possible changes into account.
Placeholder state handles should still be replaced for both private and shared state eventually - either as part of this or of a new ticket (see also FLINK-23461).