batches: re-applying a batch change that mutates the code host state puts the reconciler into an infinite operation loop

Created by: LawnGnome

The database worker is giving the Batch Changes reconciler worker a stale view of the reconciler_state column, which means that the reconciler worker would write the reconciler state back as queued instead of processing, which meant that the changeset would never be considered completed and would then be re-processed in an infinite loop.