Handle explicit empty database batches

[trask]

Treat explicit empty database batches as batches in the shared database semconv helpers. This makes db.operation.batch.size = 0 drive stable batch span naming and query summaries while continuing to omit the batch-size attribute for single-statement batches, and adds extractor tests covering the empty-batch paths.

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[Copilot]

Pull request overview

This PR updates the shared database semantic-convention helpers in instrumentation-api-incubator so that an explicit empty database batch (a batch executed with zero statements, reported as db.operation.batch.size = 0) is treated as a batch rather than as a plain non-batch statement. The batch predicate changes from batchSize > 1 to batchSize != 1, aligning it with the existing convention already used by the DynamoDB extractors. As a result, empty batches now drive stable batch span naming ("BATCH") and emit db.operation.batch.size, while single-statement batches (size 1) continue to be reported as non-batch. It also enriches multi-query batch summaries with db.operation.name/db.collection.name (for getters using singleOperationAndCollection, currently only Cassandra), and adds extractor/span-name tests for the empty-batch paths.

Changes:

• Treat batchSize == 0 (and any value != 1) as a batch across SqlClientAttributesExtractor, DbClientAttributesExtractor, and DbClientSpanNameExtractor; empty batches now yield the "BATCH" span name and emit the batch-size attribute.
• Extend MultiQuery to derive a batch-level operationName ("BATCH" / "BATCH <op>") and collectionName, exposed to the extractor when singleOperationAndCollection is enabled.
• Update JDBC, Cassandra (3.0 / common-4.0), and rediscala tests, and add new incubator extractor/span-name unit tests covering empty and single-operation multi-query batches.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
SqlClientAttributesExtractor.java	Adds emitBatchSize/isBatch (!= 1) and emits db.operation.name/db.collection.name for multi-query batches.
DbClientAttributesExtractor.java	Mirrors the != 1 batch predicate so empty batches emit db.operation.batch.size.
DbClientSpanNameExtractor.java	Returns "BATCH" for empty query-text batches and updates isBatch to != 1.
MultiQuery.java	Adds operationName/collectionName fields and builder uniqueness tracking.
SqlClientAttributesExtractorTest.java	New tests for empty single-query batch and single-operation multi-query batch attributes.
DbClientSpanNameExtractorTest.java	New tests for empty-batch span naming (stable + migration paths).
AbstractCassandraTest.java	Updates empty/batch scenarios and adds oldOperationName()/oldCollectionName() helpers.
CassandraClientTest.java (3.0)	Parallel Cassandra 3.0 test updates for the new batch behavior.
AbstractJdbcInstrumentationTest.java	Empty batch now expects span name "BATCH" with batchSize(0).
RediscalaClientTest.scala	Empty transaction scenario now asserts batchSize = 0.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated no new comments.