GH-51341: [C++][FlightRPC][ODBC] Fix statement descriptor and cursor lifecycle

[vikrantpuppala]

Rationale for this change

The Flight SQL ODBC statement implementation had a cluster of related descriptor and cursor lifecycle defects:

• the implicit application row descriptor (ARD) was initialized from the application parameter descriptor (APD), aliasing two descriptor roles;
• SQL_NULL_HANDLE did not restore built-in application descriptors;
• freeing a statement left dangling registrations in explicit descriptors;
• SQLFetch and SQLGetData without an open cursor could dereference a null result or report the wrong diagnostic; and
• SQLMoreResults did not close the current cursor when returning SQL_NO_DATA.

What changes are included in this PR?

• Initialize the active ARD from built_in_ard_.
• Map null APD/ARD assignments to the corresponding built-in descriptor and detach the outgoing explicit descriptor.
• Detach explicit descriptors before releasing a statement.
• Return SQLSTATE 24000 from SQLFetch and SQLGetData when no cursor is open.
• Close the current cursor when SQLMoreResults returns SQL_NO_DATA.
• Add public ODBC API regressions for distinct implicit descriptors, null-handle restoration, statement-before-descriptor release order, invalid cursor calls, and SQLMoreResults cursor closure.

Are there any user-facing changes?

Yes. Spec-valid descriptor release and reset sequences no longer retain dangling state, invalid cursor operations return SQLSTATE 24000, and SQLMoreResults closes the current cursor as required.

How was this patch tested?

• clang-format 19.1.7
• git diff --check
• Added focused mock/remote typed ODBC regression tests.

A fresh local CMake test configuration was blocked before compilation by the host dependency setup (a Boost CMake alias collision followed by unavailable gRPC); the full ODBC suite is left to Arrow CI.

Closes #51341.

• GitHub Issue: [C++][FlightRPC][ODBC] Fix statement descriptor and cursor lifecycle #51341

[github-actions]

⚠️ GitHub issue #51341 has been automatically assigned in GitHub to PR creator.

[Copilot]

🟡 Changes recommended

The null-handle tests do not verify that outgoing explicit descriptors are actually detached.

Get a fresh assessment by requesting another Copilot review.

Pull request overview

Fixes ODBC statement descriptor ownership and cursor lifecycle behavior.

Changes:

• Corrects implicit ARD initialization and descriptor reset/detachment.
• Adds invalid-cursor diagnostics and closes exhausted result cursors.
• Adds descriptor and cursor lifecycle regression tests.

File summaries

File	Description
odbc_statement.cc	Implements lifecycle fixes.
connection_test.cc	Tests descriptor handling.
statement_test.cc	Tests cursor diagnostics and closure.

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 1
• Review effort level: Balanced

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