Add resumable download support with tests

[ardaatahan]

This PR aims to bring over huggingface_hub Python library's resumable downloads logic to swift-transformers:

• Implements chunked transfer and retry logic for more reliable downloads
• Adds support for resumable downloads through range headers
• Adds configurable parameters for timeout, retries, and chunk size
• Improves error handling and size verification for downloads
• Uses temporary files during download to prevent corruption of existing files
• Adds new tests to verify functionality of resumable downloads
• Fixes testDeepSeekQwenChatTemplate function which was previously validating an outdated chat template output. The test now includes the correct tokens, referenced from the tokenizer repo

[pcuenca]

cc @greenrazer, would you like to give it a go at testing / reviewing this? or @FL33TW00D if you'd be up for it.

[FL33TW00D]

Just tested this out, looks great thank you for the contribution!

EDIT: seems the hub is giving transient 504s or the build would pass :)
EDIT2: Build is now passing, happy to merge this @pcuenca

[DePasqualeOrg]

@FL33TW00D, just a suggestion, but maybe squash the commits before merging next time, so that the repo's commit history doesn't get cluttered. I think you can also set this as a setting on the repo.

[FL33TW00D]

@DePasqualeOrg Whoops! Used to my repos being set to squash by default. I don't seem to have the power to change it @pcuenca

[pcuenca]

Changed! Sorry, it used to be just me merging PRs :)