Improve 'list datasets' endpoint - Python SDK

I would like to suggest a new feature on "list datasets" endpoint. It would be extremely helpful to have the count of files (of specific MIME types) included as a property in the response.

Currently, as an example, to determine the number of .pdf and .docx files in a specific dataset, we would make two separate requests to the files.aggregate() endpoint - each filtered by the datasetId and the mimetype (one request for each MIME type). This approach becomes inefficient when we need to evaluate this information across many datasets, as it requires too many requests.

If we need this information from many datasets, we should to list them, and then retrieve the count of files available through files.aggregate(). The proposed solution is to enhance data_sets.list() endpoint by adding a 'files' filter, allowing us to send an array of MIME types. The response would include the datasets that contains that specific file types, along with the files counts.

Thank you in advance!