Add the revision CheckpointInfo.from_hf_repo()

[gabrieldemarmiesse]

Checklist

• Read CONTRIBUTING.md, and accept the CLA by including the provided snippet. We will not accept PR without this.
• Run pre-commit hook.
• If you changed Rust code, run cargo check, cargo clippy, cargo test.

PR Description

The revision is quite useful for a few cases:

• being resilient to code and model changes (old versions of the code still work even after modifying the hf repo)
• When using the revision, if the files are already downloaded, there is no call to HF being done to check if a new version of the file is available leading to 1) faster loading and 2) possible offline use