Enhance Cursor close handling and context manager exception management to prevent server side resource leaks (#554)

* Enhance Cursor close handling and context manager exception management

* tests

* fmt

* Fix Cursor.close() to properly handle CursorAlreadyClosedError

* Remove specific test message from Cursor.close() error handling

* Improve error handling in connection and cursor context managers to ensure proper closure during exceptions, including KeyboardInterrupt. Add tests for nested cursor management and verify operation closure on server-side errors.

* add

* add

Signed-off-by: varun-edachali-dbx <varun.edachali@databricks.com>

Author: madhav-db

tests/unit/test_client.py

@@ -218,6 +218,15 @@ def test_context_manager_closes_cursor(self):
         finally:
             cursor.close.assert_called()
 
+        connection = databricks.sql.connect(**self.DUMMY_CONNECTION_ARGS)
+        connection.close = Mock()
+        try:
+            with self.assertRaises(KeyboardInterrupt):
+                with connection:
+                    raise KeyboardInterrupt("Simulated interrupt")
+        finally:
+            connection.close.assert_called()
+
     def dict_product(self, dicts):
         """
         Generate cartesion product of values in input dictionary, outputting a dictionary