It's possible for a remote query to the config.chunks to return results containing chunks that change version epoch in the middle, if the query executes around a drop and recreate of a collection. The ShardServerCatalogCacheLoader currently schedules such results for persistence and deals with it down the line. Instead, it should just avoid scheduling such tasks, and thus avoid special handling later.

An ConflictingOperationInProgress error must be returned to the caller if mixed results are found, to meet the CatalogCache's expectations.