[Config-parquet-and-info] Compute estimated dataset info
This will be useful to show the estimate number of rows of datasets that are partially converted to Parquet

I added `estimated_dataset_info` to the` parquet-and-info` response.
It contains estimations of:
- download_size
- num_bytes
- num_examples

Then we'll be able to propagate this info to the `size` jobs and then to `hub-cache`.

I'll run it on some datasets to check if it works fine and when it's ok I'll re-run the jobs for datasets for which we need to estimate the number of rows.


TODO:
- [x] compute sizes of non-read files
- [x] test with compressed files
- [x] test with zip archives
- [x] add track_read() test (will add before merging)
[Config-parquet-and-info] Compute estimated dataset info: This will be useful to show the estimate number of rows of datasets that are partially converted to Parquet

I added `estimated_dataset_info` to the` parquet-and-info` response.
It contains estimations of:
- download_size
- num_bytes
- num_examples

Then we'll be able to propagate this info to the `size` jobs and then to `hub-cache`.

I'll run it on some datasets to check if it works fine and when it's ok I'll re-run the jobs for datasets for which we need to estimate the number of rows.


TODO:
- [x] compute sizes of non-read files
- [x] test with compressed files
- [x] test with zip archives
- [x] add track_read() test (will add before merging)