[coverage] Conformance findings: RESULTFETCH-019

[peco-engineer-bot]

Surfaced by the multi-language coverage fan-out while conformance-testing these SPEC-IDs against databricks/databricks-jdbc.

Each is committed as an expected-failure (xfail) test in the coverage PR — the test asserts the CORRECT behavior and stays red until this driver is fixed.

• RESULTFETCH-019: ResultSet.isAfterLast() stays false after next() returns false — the Thrift streaming result impls (StreamingColumnarResult/StreamingInlineArrowResult) decrement globalRowIndex on the exhausting next(), so getCurrentRow() never reaches totalRows and the isAfterLast() comparison never holds
• RESULTFETCH-019: ResultSet.isAfterLast() stays false after next() returns false on SEA — ArrowStreamResult.next() returns early without incrementing currentRowIndex, so getCurrentRow() stays at totalRows-1 and isAfterLast() never becomes true

Reference driver PR: databricks/databricks-sql-nodejs#465
Coverage PR (reproducing xfail tests): https://github.com/databricks/databricks-driver-test/pull/994