Document adapter interface for NoSQL database operations.
Implement this interface to create drivers for specific document stores (e.g., Google Cloud Datastore, DynamoDB, Firestore). The Collection class wraps adapters with Task/Stream semantics.
For connection lifecycle management, use DocumentConnector which produces adapters.
Executes a native query and yields results as an AsyncIterable. The adapter handles underlying pagination (e.g., Datastore's endCursor or DynamoDB's LastEvaluatedKey) internally.