Fix complete_tester helper function in conftest.py so it passes all of the correct arguments to app.complete()

This fixes all of the test_argparse_comleter.py tests.

There are still failing tests in test_cmd2.py, test_history.py, and test_run_pyscript.py as well as a test in test_cmd2.py that gets stuck.

Author: tleonhardt

tests/conftest.py

@@ -151,7 +151,7 @@ def get_endidx() -> int:
         mock.patch.object(readline, 'get_begidx', get_begidx),
         mock.patch.object(readline, 'get_endidx', get_endidx),
     ):
-        return app.complete(text, 0)
+        return app.complete(text, 0, line, begidx, endidx)
 
 
 def find_subcommand(action: argparse.ArgumentParser, subcmd_names: list[str]) -> argparse.ArgumentParser: