Replace duplicate Async* batch namespace classes with sync imports

AsyncBatchRecordOperations, AsyncBatchTableOperations,
AsyncBatchQueryOperations, AsyncBatchDataFrameOperations, and
AsyncChangeSetRecordOperations were byte-for-byte copies of their sync
counterparts with no async methods or I/O. They are removed and the sync
classes from operations.batch are imported and used directly.

AsyncChangeSet is kept — it needs __aenter__/__aexit__ for
`async with batch.changeset()`.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash