fix(go): align buffers before C Data export

[dataders]

What changed

This adds an internal Go helper that prepares record batches for Arrow C Data export by copying only buffers whose base pointer is not aligned to 64 bytes.

The c-shared driver template now runs record batches through that helper before calling cdata.ExportArrowRecordBatch, and the generated c-shared driver packages have been regenerated from the template.

Why

Some consumers of Arrow C Data import primitive buffers as typed native buffers and require the pointer to satisfy the scalar type alignment. Decimal128 is backed by 16-byte values, so a Decimal128 value buffer exported through C Data with an 8-byte-aligned pointer can fail in strict consumers.

The Go drivers can receive Arrow IPC-backed buffers whose byte storage is usable inside Go but not suitable to hand out unchanged across the C Data FFI boundary. The c-shared driver owns that boundary, so it should ensure the buffers it exports are aligned.

Validation

• go test ./pkg/internal/cdataalign -count=1
• go test -tags driverlib ./pkg/flightsql ./pkg/panicdummy ./pkg/snowflake ./pkg/bigquery ./pkg/databricks ./pkg/salesforce -count=1
• Built the Snowflake c-shared driver locally with a forced-misaligned allocator repro setup.

[felipecrv]

I think the latest versions of arrow-go already guarantee alignment that satisfies arrow-rs requirements. All the drivers built from this repo are safe already.