Keep track of synthetic apify-default-dataset-item events

[janbuchar]

• Port over fix: Keep track of synthetic apify-default-dataset-item events apify-sdk-js#528
  • We should wait until the JS changes are released and tested to prevent duplicating efforts
  • The monkey patching part may not be necessary - the ApifyStorageClient Python class might be a good place for the synthetic event accounting logic
• Related - calculate_max_event_charge_count_within_limit doesn't do it's job when pushing data to default dataset in PPE actor #705