Add `ingestBatch` method to generated datasource accessors

[gnzjgo]

Description

The generated typed datasource accessors (via DatasourceAccessor in src/schema/project.ts) only expose:

• ingest(event) — single event
• append(options)
• replace(options)
• delete(options)
• truncate(options)

There is no ingestBatch(events: TRow[]) method, even though the underlying client supports it (client.ingestBatch()) and the TypedDatasourceIngest interface defines sendBatch.

Users currently have to bypass the typed accessors and use the raw Events API to batch ingest.

Expected behavior

tinybird.myDatasource.ingestBatch(events) should work with full type inference, similar to how ingest(event) works for single events.