Which reconfiguration-target dimensions an ALTER left unset (Unchanged).
Drives fold_reconfiguration_target. Logging is two sub-dimensions
because INTROSPECTION DEBUGGING and INTROSPECTION INTERVAL are
independently alterable.
Whether an ALTER statement sets a replica config shape dimension (SIZE,
AVAILABILITY ZONES, or either INTROSPECTION option), the changes that
need a durable reconfiguration record and a hydrate-overlap.
Retains a stale in-progress reconfiguration record carried by a legacy-path
config write as cancelled, returning the audit intent to declare with the
write.