iter_archive for zip files 
And also don't always try streaming with Google Drive - it can have issues because of how Google Drive works (with quotas, restrictions, etc.) and it can indeed cause `BlockSizeError`.

Feel free to host your test data elsewhere, such as in a dataset repository on https://huggingface.co (see [here](https://huggingface.co/docs/datasets/upload_dataset.html#upload-your-files) for a tutorial on how to upload files)
* In this PR, I added the option to iterate through zipfiles for `download_manager.py` only. 
* Next PR will be the same applied to `streaming_download_manager.py`.
* Related issue #3272.
## Comments : 
* There is no `.isreg()` equivalent in zipfile library to check if file is Regular so I used `.is_dir()` instead to skip directories.
* For now I got `streaming_download_manager.py`  working for local zip files, but not for urls. I get the following error when I test it on an archive in google drive, so still working on it.  `BlockSizeError: Got more bytes so far (>2112) than requested (22)`


## Tasks : 
- [x] download_manager.py
- [ ] streaming_download_manager.py