FObjectReplicator::ValidateAgainstState may validate against the wrong buffers

In 4.14, changes were introduced to share replicated state between objects on the server (Shadow State) this was done to allow sharing property comparisons to determine when objects needed to replicate to clients.

On the server, the shared replicated state is stored in FRepChangelistState::StaticBuffer. For clients, or when receiving properties, the state is stored in FRepState::StaticBuffer.

FObjectReplicator::ValidateAgainstState was never updated to reflect that, so on the server we still use the FRepState version, which always reports errors.

1. Run a FN Server and Client.
2. On the server, make sure the "net.DormancyValidate" CVar is set to 1.
3. Gather some materials, and build something.
4. Wait a few seconds for the building actor to go dormant.
5. Hit the building actor with a pickaxe (or any weapon)

Expected:
No warnings are logged

Actual:
Warnings like "FDiffPropertiesImpl: Property different: <PropertyType> <PathToProperty> always complain about being different when the actor becomes dormant and when it becomes no longer dormant.