path: update `get_unique_pull_path` to point out it returns a url Unlike other functions in this module it returns a url as `bytes` and not a `path` object. Let us point it out in the doc.

changelog-v2: fix the docket `struct` The previous definition used `L` which is actually 4 bytes, while the documentation and intend was to use `Q`, i.e. 8 bytes.

path: pass `path` to `peer` in infinite push We directly use the `path` object to build the `peer` object.