The hook currently checks that a collection's UUID is the same between the sharding catalog (that is, config.collections on the config server) and

• shards' storage catalogs (via listCollections output)
• shards' catalog caches (in config.cache.collections)

This ticket is to add a check that a database's UUID is the same between the sharding catalog (that is, config.databases on the config server) and

• shards catalog caches (in config.cache.databases)