elastic_ecs module raises spurious exception for STIX 2.1 results

[pcoccoli]

Describe the bug
When you set the "stix_2.1": True option, you get a bogus exception:

RuntimeError: Incorrect number of result objects after translation. Found: 23, expected: 2.

There is code in the result translation that attempts to count the translated results and compare that with the native results (why?), but it only works for STIX 2.0. I recommend removing the check entirely; it doesn't really serve any purpose.

Afer doing some grep'ing, I think the proofpoint connector has the same problem.

To Reproduce

python main.py -d execute elastic_ecs elastic_ecs:beats '{"type":"identity","name":"test","id":"identity--8334a815-a920-4ac8-8168-51aa3755b337"}' '{"host":"example.com","port":9200,"indices":"winlogbeat-*","selfSignedCert": false, "options": {"stix_2.1": true}}' '{"auth":{"id":"my-id","api_key":"my-key"}}' "[process:command_line LIKE '%wmiprvse.exe%'] START t'2022-05-14T00:00:00Z' STOP t'2022-05-15T00:00:00Z'"

Expected behavior
It should not raise any exceptions.

Screenshots

 2023-01-30 14:33:44,557 stix_shifter_utils.stix_translation.stix_translation_error_mapper ERROR    received exception => RuntimeError: Incorrect number of result objects after translation. Found: 23, expected: 2.
 2023-01-30 14:33:44,557 stix_shifter_utils.stix_translation.stix_translation_error_mapper DEBUG      File "/home/pcoccoli/github/stix-shifter/main.py", line 4, in <module>
    main()
  File "/home/pcoccoli/github/stix-shifter/stix_shifter/scripts/stix_shifter.py", line 305, in main
    result = translation.translate(args.module, 'results', args.data_source, json.dumps(results), translation_options)
  File "/home/pcoccoli/github/stix-shifter/stix_shifter/stix_translation/stix_translation.py", line 138, in translate
    return entry_point.translate_results(data_source, data)
  File "/home/pcoccoli/github/stix-shifter/stix_shifter_utils/utils/base_entry_point.py", line 68, in wrapper_func
    return func(self, *args, **kwargs)
  File "/home/pcoccoli/github/stix-shifter/stix_shifter_utils/utils/base_entry_point.py", line 179, in translate_results
    ErrorResponder.fill_error(result, message_struct={'exception': ex})
  File "/home/pcoccoli/github/stix-shifter/stix_shifter_utils/utils/error_response.py", line 117, in fill_error
    ErrorResponder.call_module_error_mapper(message_struct, return_object, connector)
  File "/home/pcoccoli/github/stix-shifter/stix_shifter_utils/utils/base_entry_point.py", line 176, in translate_results
    return translator.translate_results(data_source, data)
  File "/home/pcoccoli/github/stix-shifter/stix_shifter_modules/elastic_ecs/stix_translation/results_translator.py", line 38, in translate_results
    raise RuntimeError("Incorrect number of result objects after translation. Found: {}, expected: {}.".format(len(results['objects']) - 1, len(json_data)))

  <class 'RuntimeError'> Incorrect number of result objects after translation. Found: 23, expected: 2.

Additional context
git commit a9e5b43