fix(jans-cli-tui): save config-api configuration

[devrimyatar]

When saving config-api configuration, this error riases:

Unhandled exception in event loop:
  File "/usr/lib/python3.10/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/application/application.py", line 707, in read_from_input
    self.key_processor.process_keys()
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/key_binding/key_processor.py", line 270, in process_keys
    self._process_coroutine.send(key_press)
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/key_binding/key_processor.py", line 185, in _process
    self._call_handler(matches[-1], key_sequence=buffer[:])
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/key_binding/key_processor.py", line 320, in _call_handler
    handler.call(event)
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/key_binding/key_bindings.py", line 124, in call
    result = self.handler(event)
  File "/usr/local/lib/python3.10/dist-packages/prompt_toolkit/widgets/base.py", line 466, in _
    self.handler()
  File "/mnt/data/projects/Janssen/jans/jans-cli-tui/cli_tui/plugins/140_config_api/main.py", line 664, in save_config
    new_data = self.make_data_from_dialog(tabs={'main_': self.tabs['main_']})
  File "/mnt/data/projects/Janssen/jans/jans-cli-tui/cli_tui/utils/utils.py", line 72, in make_data_from_dialog
    for item in process_tabs[tab].children:

Exception 'ScrollablePane' object has no attribute 'children'