The ShardingCatalogClient interface represents the main API a mongos process may use to access metadata on the config server.

The objectives of this ticket are:

• extend such interface to also include the ListOfShards getShardsThatOwnDataForCollAtClusterTime(collName, clusterTime) method
• implement the new method to access the content of config.placement and config.shards (this other function may serve as a reference for how to send an aggregation to the config server)
• include unit tests for the method