GH-48119: [C++][ODBC] Move class definitions to type_fwd.h

[AestheticAkhmad]

Rationale for this change

This PR addresses the issue #48119

What changes are included in this PR?

Create type_fwd.h with forward declarations for ODBC classes to reduce compilation dependencies:

• Add new type_fwd.h with forward declarations for Statement, ResultSet, ResultSetMetadata, ODBCEnvironment, ODBCDescriptor, ODBCStatement, and ODBCConnection
• Replace full header includes with type_fwd.h
• Remove duplicate forward declarations from existing headers
• Update CMakeLists.txt to include new header

Are these changes tested?

No

Are there any user-facing changes?

No

• GitHub Issue: [C++][Flight SQL ODBC] Move class definitions to a type_fwd.h file #48119

[github-actions]

Thanks for opening a pull request!

If this is not a minor PR. Could you open an issue for this pull request on GitHub? https://github.com/apache/arrow/issues/new/choose

Opening GitHub issues ahead of time contributes to the Openness of the Apache Arrow project.

Then could you also rename the pull request title in the following format?

GH-${GITHUB_ISSUE_ID}: [${COMPONENT}] ${SUMMARY}

or

MINOR: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - Contributing Overview

[github-actions]

⚠️ GitHub issue #48119 has been automatically assigned in GitHub to PR creator.

[github-actions]

⚠️ GitHub issue #48119 has been automatically assigned in GitHub to PR creator.

[lidavidm]

CC @alinaliBQ

[github-actions]

⚠️ GitHub issue #48119 has been automatically assigned in GitHub to PR creator.

[alinaliBQ]

@lidavidm Could you please help approving the CI workflows for this PR?

[lidavidm]

The formatter has some complaints:

diff --git a/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/connection.h b/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/connection.h
index 6feb5f208a..5418489169 100644
--- a/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/connection.h
+++ b/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/connection.h
@@ -26,8 +26,8 @@
 #include <vector>
 
 #include "arrow/flight/sql/odbc/odbc_impl/diagnostics.h"
-#include "arrow/flight/sql/odbc/odbc_impl/types.h"
 #include "arrow/flight/sql/odbc/odbc_impl/type_fwd.h"
+#include "arrow/flight/sql/odbc/odbc_impl/types.h"
 
 namespace arrow::flight::sql::odbc {
 
diff --git a/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/result_set.h b/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/result_set.h
index 1832be6943..b4a3994ca3 100644
--- a/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/result_set.h
+++ b/cpp/src/arrow/flight/sql/odbc/odbc_impl/spi/result_set.h
@@ -22,8 +22,8 @@
 
 #include "arrow/flight/sql/odbc/odbc_impl/platform.h"
 
-#include "arrow/flight/sql/odbc/odbc_impl/types.h"
 #include "arrow/flight/sql/odbc/odbc_impl/type_fwd.h"
+#include "arrow/flight/sql/odbc/odbc_impl/types.h"
 
 #include <sqltypes.h>
 
diff --git a/cpp/src/arrow/flight/sql/odbc/odbc_impl/type_fwd.h b/cpp/src/arrow/flight/sql/odbc/odbc_impl/type_fwd.h
index dbec55d301..54e592949b 100644
--- a/cpp/src/arrow/flight/sql/odbc/odbc_impl/type_fwd.h
+++ b/cpp/src/arrow/flight/sql/odbc/odbc_impl/type_fwd.h
@@ -21,7 +21,7 @@ namespace arrow::flight::sql::odbc {
 class Statement;
 class ResultSet;
 class ResultSetMetadata;
-}
+}  // namespace arrow::flight::sql::odbc
 
 // TODO: Replace ODBC namespace with namespace arrow::flight::sql::odbc #48083
 namespace ODBC {
@@ -29,4 +29,4 @@ class ODBCEnvironment;
 class ODBCDescriptor;
 class ODBCStatement;
 class ODBCConnection;
-}
+}  // namespace ODBC