When generating API stubs with the scaffold utility using, e.g., `python -m localstack.aws.scaffold sns`,
the scaffold creates method names from operation names, which are ugly when acronyms (subsequent uppercase characters that belong together).

Example:
`CreateSMSSandboxPhoneNumber` -> `create_s_m_s_sandbox_phone_number`

it would be nicer to have `create_sms_sandbox_phone_number`

This is a limitation of this method: https://github.com/localstack/localstack/blob/1888e66b85d7e6a8ee457bc7a732984fcf7aa830/localstack/utils/common.py#L978-L979
tmp_dir = new_tmp_dir()
        assert is_empty_dir(tmp_dir)
        def _check(fname, is_dir):
            test_entry = os.path.join(tmp_dir, fname)
            mkdir(test_entry) if is_dir else save_file(test_entry, "test content")
            assert not is_empty_dir(tmp_dir)
            assert is_empty_dir(tmp_dir, ignore_hidden=True) == (fname == ".hidden")
            rm_rf(test_entry)
            assert is_empty_dir(tmp_dir)
        for name in ["regular", ".hidden"]:
            for is_dir in [True, False]:
                _check(name, is_dir)
    def test_create_archive(self):