MetadataManager directly calls into the CatalogCache

The MetadataManager class, which contains the sharding filtering information incorrectly references the catalog cache. This is wrong because if the cache doesn't contain the filtering information for the specified collection, it will return empty filtering information, which may lead to incorrect results from being returned.

This is not a problem in 4.0 because the createMetadataAt method is not used, but will be in 4.2 when we start supporting sharded read-only transactions.