[Java] Add experimental Arrow Flight support

[danilonajkov-db]

What changes are proposed in this pull request?

Adds Arrow Flight ingestion to the Java SDK. The Java side accepts VectorSchemaRoot directly, serializes to IPC bytes internally, and passes them across the JNI boundary where the Rust SDK handles encoding, framing, and transmission over the Arrow Flight gRPC protocol.

• New ZerobusArrowStream with ingestBatch(), waitForOffset(), flush(), close(), getUnackedBatches()
• New ArrowStreamConfigurationOptions with builder pattern
• New SDK methods: createArrowStream(), recreateArrowStream()
• Opt-in: add arrow-vector and arrow-memory-netty as dependencies (provided scope, >= 15.0.0)
• Integration tests and example in examples/arrow/

How is this tested?

Added arrow flight integration tests

[danilonajkov-db]

how should we handle this case? I think throwing an exception makes sense, but we can make it a no-op too.

[teodordelibasic-db]

For the regular gRPC stream the return type is Optional<Long> and we return an empty option, so I think matching that would be okay.